Abstract: The method of detecting the hydrogen concentration by using a first heat-generating resistor of which a first electrophysical quantity varies depending upon the hydrogen concentration and a second heat-generating resistor which is neighboring said first heat-generating resistor in a direction of gas flow and of which a second electrophysical quantity varies depending upon the hydrogen concentration as does the first electrophysical quantity, to detect the concentration of hydrogen based on the first electrophysical quantity and the second electrophysical quantity, the method comprising: calculating the amount of change in a target physical quantity, which is either the first electrophysical quantity or the second electrophysical quantity, calculating the correction amount based on a difference between the first electrophysical quantity and the second electrophysical quantity, and a calculating the concentration of hydrogen based on a difference between the amount of change in the target physical quantity and

Abstract: A method of detecting hydrogen concentration, while maintaining high precision, is provided.

Abstract: A method of plating a semiconductor wafer while maintaining a uniform thickness of the plated film, preventing the precipitation on the back surface of the wafer and preventing the contamination in the subsequent steps. In directly forming connection terminals on the aluminum electrodes on the semiconductor wafer, the non-electrolytic plating is effected in a state where the back surface of the wafer is covered with an insulator. The insulator is preferably a glass substrate which is a part constituting the product. A semiconductor type sensor exhibits improved corrosion resistance against a corrosive medium. The semiconductor type sensor has, in a semiconductor substrate, a structural portion for detecting the physical quantity or the chemical component of a corrosive medium and an electric quantity conversion element, and has pads which are the output terminals for sending the detected electric signals to an external unit, wherein the pads are protected by a precious metal.