An electrode film and a protective electrode film are formed on an insulating film and a first magnetic film in turn. A method for producing a probe for light detection or light irradiation which comprises the steps of working a substrate to form a groove therein, forming a flat plate-shaped cover portion on the groove to form a hollow waveguide having an opening in a part thereof, forming a hollow tip having a microaperture on the opening, and removing a part of the substrate by etching, to form a cantilever. With this construction, it is possible to suppress a depression operation load to a low level at a time of depressing input operation, and, when contact switches with click feel are depressed, the click feel can be easily transmitted. The invention is also characterized in that the measuring instrument controls the composition in accordance with a function of the detected viscosity by means of the circuit for controlling the means or that it is located downstream of the means for changing the composition and that it controls the composition of the oxidation agentfuel mixture by means of the circuit for controlling the means. 2 \u2003\u20030\u22661-a-b\u22660.