<p>Provided are a retainer in which an inner dead space can be reduced, and an air bag device having the retainer. The retainer (10) includes a bottom surface part (11) and a peripheral wall part (12) extending forward from the peripheral edge of the bottom surface part (11). A mounting part (11a) to which an inflator (30) is attached is formed near the longitudinal center of the bottom surface part (11). The portion of the bottom surface part (11) between the mounting part (11a) and the peripheral wall part (12) is formed as a tilted part (11b) that is tilted forward in the direction toward the peripheral wall part (12) side. The amount (P) of the projection of the tilted part (11b) forward from the mounting part (11a) on the outermost periphery of the bottom surface part (11) is almost equal to the amount (H) of the projection of the inflator (30) from the mounting part (11a).</p>
