IGNITER AND GAS GENERATOR

Provided are an igniter and a gas generator that suppress inhibition of fire transfer to an enhance agent by adjusting elongation of a cup-shaped member at the time of activation while maintaining sealability and insulation. A disk-type gas generator has a short substantially cylindrical housing in which one end and the other end in an axial direction are closed, and a holder , an igniter including a squib cover , a cup-shaped member , an enhance agent , a gas generating agent , a lower support member , an upper support member , a cushion material , a filter , and the like as internal components are accommodated in an accommodation space provided inside the housing. The squib cover is formed by molding a thermosetting resin or a thermoplastic resin containing an elongation percentage adjusting material into a cup shape in order to set an elongation percentage at the time of activation of the igniter to be greater than 0% and less than 10%.