Tear structure of air bag door

Movable reinforcing panels (31) are respectively formed with a plurality of serially-combined panel members (31a) disposed along bending lines of opening door panels (13) and (14). The panel members (31a) are coupled together deformably with a ranging portion (33) for partially coupling together the end edge portions of the adjoining panel members (31a) and fitted to a fixing bracket (26) via coupling members (32). When an air bag starting to inflate presses any one of the panel members (31a) of the movable reinforcing panels (31) upward after an air bag system is operated, regions corresponding to the movable reinforcing panels (31) of the door panels (13) and (14) are deformed outward. Thus, tear seams (15) and (16) situated closest to the deformed regions are first caused to partially rupture and then these tear seams (15) and (16) are totally ruptured.