Abstract: To provide reduction in size of an igniter device and a gas generator by enhancing strength of a plug under high temperature and thereby reducing thickness of the plug, and to surely prevent electrode pins being burst forth from the plug. An igniter device comprising a resistance heating element, gunpowder to be ignited by heat generation of the resistance heating element, electrode pins connected to the resistance heating element, and a plug for holding the electrode pins, wherein material of the plug is a thermosetting resin. A gas generator comprising a cup packed with gas generant to generate gas by burning, an igniter device arranged in an interior of the cup, and a holder for holding the igniter device and the cup, wherein the holder has insertion holes for allowing the electrode pins to extend through them, respectively.