Abstract: A resist on an electronic material is surely separated and removed in a short time. The electronic material is cleaned with a sulfuric acid solution containing persulfuric acid to separate and clean the resist, and thereafter wet cleaning is performed with gas dissolved water. By using gas dissolved water for performing wet cleaning after the resist separation with the sulfuric acid solution containing persulfuric acid, the time required for cleaning can be sharply reduced as compared with that of a former method. The sulfuric acid solution containing persulfuric acid is preferably one produced by electrolyzing a sulfuric acid solution.

Abstract: By performing thermal fusion bonding in the state where a bonding portion is covered with a bonding portion cover and the concentrations of oxygen and moisture inside the bonding portion cover are set lower than the concentrations of oxygen and moisture in the atmosphere, it is possible to reduce elution from a bonded resin-based pipe.

Abstract: An apparatus for supplying water containing dissolved gas comprising a flowmeter for measuring a flowrate of pure or ultra-pure water and a mechanism for controlling a flowrate, a means for adjusting an amount of water which adjusts an amount of the pure or ultra-pure water supplied to the apparatus for dissolving a gas, a tank which receives the water containing dissolved gas in an excessive amount which is not used at a point of use, a piping system through which the water containing dissolved gas glows from the tank towards the point of use and the water containing dissolved gas in an excessive amount returns to the tank, a piping system for supplying the water containing dissolved gas to the tank, and a controlling means for adjusting an amount of water based on a water level in the tank.

Abstract: An apparatus for supplying water containing dissolved gas comprising a flowmeter for measuring a flowrate of pure or ultra-pure water and a mechanism for controlling a flowrate, a means for adjusting an amount of water which adjusts an amount of the pure or ultra-pure water supplied to the apparatus for dissolving a gas, a tank which receives the water containing dissolved gas in an excessive amount which is not used at a point of use, a piping system through which the water containing dissolved gas glows from the tank towards the point of use and the water containing dissolved gas in an excessive amount returns to the tank, a piping system for supplying the water containing dissolved gas to the tank, and a controlling means for adjusting an amount of water based on a water level in the tank.

Abstract: By performing thermal fusion bonding in the state where a bonding portion is covered with a bonding portion cover and the concentrations of oxygen and moisture inside the bonding portion cover are set lower than the concentrations of oxygen and moisture in the atmosphere, it is possible to reduce elution from a bonded resin-based pipe.

Abstract: An apparatus for continuous dissolution comprising a dissolution portion for dissolving a gas into a main stream liquid, which comprises a flow meter measuring the flow rate of the main stream liquid and outputting a signal of the value obtained by the measurement and a mechanism for controlling the flow rate which controls the amount of supply of the gas based on the input signal; and a process for continuously dissolving a gas into the main stream liquid, wherein the amount of the gas is controlled based on the flow rate of the main stream liquid. Since a solution having a constant concentration can be obtained with stability even when the flow rate of the main stream liquid changes, cleaning water or surface treatment water used for electronic materials which particularly require a precisely clean surface can be supplied without loss.

Abstract: An apparatus for producing water containing dissolved ozone which comprises (A) a piping for supplying ultrapure water through which ultrapure water is supplied, (B) a catalytic reaction portion which is connected with the piping for supplying ultrapure water and in which the ultrapure water is brought into contact with an oxidation-reduction catalyst, (C) a filtration apparatus by which the ultrapure water treated in the catalytic reaction portion is filtered and (D) an apparatus for dissolving ozone in which ozone is dissolved into the ultrapure water discharged from the filtration apparatus; and an apparatus for producing water containing dissolved ozone which comprises an apparatus for producing ultrapure water which is equipped with an apparatus for irradiating with ultraviolet light, an apparatus for dissolving ozone in which ozone is dissolved into the ultrapure water produced in the apparatus for producing ultrapure water and a catalytic reaction portion which is packed with an oxidation-reduction cat