Gas generator and gas discharge method for gas generator

A gas discharge method, comprising:

• preparing a housing of the gas generator, the housing accommodating, inside thereof, an igniter and a gas generating agent that generates a combustion gas by being combusted in response to actuation of the igniter, the housing including a gas discharge port penetrating through the housing from an inside to an outside of the housing, the gas discharge port including a chamfered region in which a corner portion of an opening on an inner surface of the housing is removed over an entire circumference of the opening;
• closing the gas discharge port by attaching a seal to the inner surface of the housing and by covering the opening of the gas discharge port on the inner surface of the housing;
• assembling the gas generator;
• activating the igniter;
• and
• rupturing the seal in such a manner that at least a part of the seal remains at the gas discharge port by pressing the seal against an inner wall surface of the chamfered region with a pressure of the combustion gas generated in response to the actuation of the igniter and by rupturing a region of the seal that is on an inner side of a contact region of the seal, the contact region being a region which is in contact with the inner wall surface of the chamfered region.