NOVELTY - A gas measuring system comprises temperature measuring element (62) being in contact with gas; heater (61) producing heat at several heat producing temperatures; measuring unit measuring value for electric signal from a temperature measuring element; equation storage device storing an equation that includes independent variables that represent electric signals from the temperature measuring element and electric signals from the heating element at the heat producing temperatures; and calculator.    USE - As gas measuring system used in electric power generating system (claimed).    ADVANTAGE - The device is able to measure accurately the amount of hydrogen provided to the fuel cell; is able to measure accurately the quantity of atoms that structure molecules included in a gas in a variety of fields, not limited to fuel cells; and is able to evaluate the number of atoms that structure molecules included in a gas. It possible to generate an equation, able to calculate uniquely the sum of the products of the numbers of hydrogen atoms that structure the molecules included in the respective mixed gases, the atomic weight of hydrogen, and the volumetric ratios of the respective molecules.    DETAILED DESCRIPTION - A gas measuring system comprises a temperature measuring element (62) being in contact with a gas; heater (61) being in contact with the gas and producing heat at several heat producing temperatures; a measuring unit measuring a value for an electric signal from a temperature measuring element that is dependent on the temperature of the gas, and a value for an electric signal from a heating element at each of heat producing temperatures; an equation storage device storing an equation that includes independent variables that represent electric signals from the temperature measuring element and electric signals from the heating element at the heat producing temperatures and a dependent variable that represents the sum of the products of the respective numbers of atoms that structure the molecules included in the gas, the atomic weight of the atoms, and the volumetric ratios of the respective molecules; and a calculator calculating a value that represents the sum of the products of the respective numbers of atoms that structure the molecules included in the gas, the atomic weight of the atoms, and the volumetric ratios of the respective molecules, by substituting, into the independent variables in the equation, values for the electric signals from the measuring element and values for the electric signals from the heating element. An INDEPENDENT CLAIM is included for An electric power generating system comprising the gas measuring system; a fuel cell being supplied with hydrogen extracted from the gas; and a controlling device controlling the amount of hydrogen provided to the fuel cell, based on the value indicated by the calculated product.    DESCRIPTION OF DRAWING(S) - The figure shows first perspective view of a microchip.    Microchip (8)    Thermally insulating member (18)    Substrate (60)    Heater (61)    Temperature measuring elements (62, 63)    Temperature maintaining element (64)    Insulating layer (65)