A head-protecting airbag device includes: an airbag including: an airbag body; and a connecting tab connected with a mounting bracket, wherein the mounting bracket includes: a mounting piece mounted on the body with a fixing means; and a connecting piece formed to project to both sides from a lower end of the mounting piece, and connected with the airbag; in the connecting tab, an insertion hole, into which the mounting piece is inserted, is disposed in a folded portion; the connecting tab includes a front side portion and a back side portion which extend from the folded portion to the airbag body and cover a font side and a back side of the connecting piece; and a loop coupling portion is disposed in a position where the mounting piece having the connecting piece stored in the connecting tab is prevented from coming off the insertion hole.