Abstract: Provided is a stripping method capable of stripping a resist while suppressing the time and cost of processing required for stripping, while giving sufficient consideration to the load on the environment. The resist stripping method is a method for stripping a resist film-formed on a substrate, including: a pretreatment step of exposing the resist to a heated steam in a predetermined temperature range for a predetermined time; and a stripping step of stripping the resist exposed to the heated steam in the pretreatment step by using a resist stripping liquid, wherein the predetermined temperature range and the predetermined time are set according to the resist.

Abstract: A power conversion equipment or apparatus includes an AC/DC conversion circuit which rectifies and converts an alternating current power source to a direct current, and a DC/AC conversion circuit which converts the direct current to a high frequency three-phase alternating current voltage having 3N pulses times a fundamental wave frequency in a half cycle, the fundamental wave frequency being higher than the frequency of the alternating current power source. The power conversion equipment also includes a three-phase high frequency transformer having a primary winding that is connected to the output of the DC/AC conversion circuit, a rectifier circuit which rectifies a secondary winding voltage of the three-phase high frequency transformer, and a filter circuit connected to the direct current output of the rectifier circuit.

Abstract: An object of the present invention is to prevent erroneous operation of a liquid level sensor due to deposition of ammonium fluoride dissolved in buffered hydrofluoric acid used as a process solution.The present invention provides a liquid level sensor comprising a chemical solution bath for receiving a chemical solution including buffered hydrofluoric acid, a gas feed tube for introducing a gas for detecting the variation in the liquid level of said chemical solution into said chemical solution, and a gas pressure detector for detecting a change in the pressure of said gas and converting it into an electric signal to indicate a change in liquid level, characterized in that the diameter of a gas outlet provided at an end of said gas feed tube is smaller than the inner diameter of said gas feed tube.