The invention, and the ignition means accommodated in a tubular housing having a gas discharge port, and a gas generator having a gas-filled wonsil the inflation gas source is charged, is disposed within the tubular housing to close the discharge path of the gas and a closure member for, a support structure of the closure member comprising a combination of a support member of the closure member, the support member, having a first support member on an extended projection in a direction from the base portion, and a center of the base portion , and will also having a passage gas holes in at least a portion of the base portion and the projections on the first support member, said closure member, will first substrate having a surface and a second surface, wherein the closure member, wherein the first surface or is supported in the center of the second face of the first support member from the front end face by the abutment surface side of the projection Shall in the first securing member has a annular surface that does not contact with, and provides a support structure of the obstruction member of the gas generating appointed to the said annular surface of said closure member is opened by being cleaved.