PURPOSE: To allow an inflator for an occupant protecting device, formed to include a mechanical ignition type sensor and the like, to be easily operated forcibly in the state of being fitted to a vehicle at the time of motor vehicle cessation or the like.

CONSTITUTION: A squib 76 is disposed at an inflator 18. A contact 82 can be connected to this squib 76 from the outside. At the time of motor vehicle cessation or the like, a worker connects the contact 82 to the squib 76 from the outside and turns a switch on. Then a current flows to the squib 76, and a gas generating agent 26 is burnt. The inflator 18 and in its turn an air bag device can be thereby forcibly operated in the state of being fitted to the vehicle.