PURPOSE:To perform a positive ignition and maintain a safety when an ignition failure occurs, by a method wherein, after ignition of a burner, an electromagnetic valve is opened by a DC power source within a time for which a thermocouple generates a sufficient electromotive force by the use of heat. CONSTITUTION:After several seconds have elapsed after closed, a gas igniter 3 is energized through a timer switch 2 for releasing. Through the working of the timer switch 2, an electromagnetic coil 6 for an electromagnetic valve 5 located in a gas feed path is energized through a diode 4. The gas igniter 3 is provided with a discharge electrode 7 and is positioned so as to ignite a burner 8. A thermocouple 9 is connected in parallel to said electromagnetic coil 6, the thermocouple being located in the vicinity of the burner so as to be subject to the heat generated by the burner 8. Further, a heat-sensitive resistance 10 having a negative temperature coefficient is inserted into a circuit for the thermocouple 9, the resistance 10 being placed in a position where the resistance is subject to the heat produced by the burner 8. This enables to perform a reliable ignition and maintain safety when an ignition failure occurs through a simple ignition operation even during the use of the thermocouple.