A vehicle hood airbag device in which an in-hood reinforcement (28) is arranged in a hood width direction at a rear end portion of an inner hood panel (20). The in-hood reinforcement (28) has longitudinal opposite end portions coupled to left and right hood hinge reinforcements (40) that are disposed on the respective lateral sides of the inner hood-panel (20) to increase the rigidity of the inner hood panel (20). Further, by fixing the airbag case (46) to the in-hood reinforcement (28), the rigidity of the inner hood panel (20) is further increased.