The present invention provides a gas generator including a combustion chamber formed inside a housing having a gas discharge port, a disk-shaped gas generating agent stacked and loaded or a single tubular gas generating agent loaded in the combustion chamber in the axial direction of the housing, an igniter disposed inside the combustion chamber to enclose the igniter and fixed to a bottom surface of the housing by a fixing member, the fixing member including a fixing portion for the igniter and a plurality of elastic rod-like gas generating agent support portions extending in the radial direction of the housing from the fixing portion, the gas generating agent support portions abutting against a surface of the gas generating agent opposing the bottom surface of the housing, and the gas generating agent being pressed and fixed between the gas generating agent support portions and a top surface of the housing.