To provide a bed device that helps change the angle of a head board to one making a user lean easily.

The bed device has a bed body 1, on the top face of which a mattress 2 is provided and a head board 3 provided at one end of the bed body, and the head board has a body portion 4, the storage portion of which is formed opened in the front, a mounting member 6 provided in the storage portion, an arm 8, the lower portion of which is connected rotatably to the mounting member and rotating from a nearly vertical state to a laid state, a backrest 13 the upper portion of which is connected to the upper portion of the arm turnably in the opposite direction of the turning direction of the arm, and the angle of opening with regard to the arm is limited to prescribed limits, and held at a state of being stored in the storage portion and a state of tilting at a prescribed angle on the mattress.