To provide airbag door structure which secures smoothness and reliability of the airbag operation so that a recessed groove forming the airbag door is easily broken at the time of airbag inflation though the recessed groove is not broken by the shock from the occupant's room, and is robust against the shock from the occupant's room.

The airbag door is composed of a door part surrounded by the recessed groove formed on the inside of an instrument panel, a chute fixed to the instrument panel so as to be in surface contact to the instrument panel at the part having the formed recessed groove, and a reinforcing member which is connected to the inner side of the door part, and has the peripheral portion connected to the suit in a stair step type.