To inexpensively improve responsiveness of a solenoid opening/closing valve of an extinguishment prevention apparatus for gas combustion instruments wherein when heat of a flame of a pilot burner is detected, fuel gas is supplied, and when the flame of the pilot burner is extinguished, the supply of the fuel gas is interrupted without complicating the construction.

A thermal power generation device 12 which is obtained by joining a P type FeSi2 semiconductor and an N type FeSi2 semiconductor, is used to detect heat of a flame of a pilot burner, and a solenoid opening/closing valve 6 is controlled with electromotive force of the thermal power generation device 12. Hereby, provided the number of windings of a coil 11 is adjusted without altering the structure of the device, such that attraction time of the solenoid opening/closing valve 6 is the same order compared with the case where a thermocouple is used, release time of the solenoid opening/closing valve 6 becomes about half, and hence responsiveness of the device upon extinguishment happening is improved. Particularly, the effect is further improved by setting a cross section in the vicinity of a junction between the p type FeSi2 semiconductor and the N type FeSi2 semiconductor of the thermal electric power generation device 12 to be smaller than other parts.