To provide a dental treatment chair enabling an aged person or a physically handicapped person to easily get on and off by making an armrest movable and guiding operations at the time of getting on and off by the armrest especially.

In the state where the armrest 16 is at a position indicated in Figure (A), a patient receives dental treatment. When the dental treatment ends, it is moved to the position indicated in Figure (B), that is the position for enabling the patient to easily get on and off at the front upper part of the position in Figure (A). At the time, when the patient puts a hand or arm on the armrest 16 and applies force, together with the movement of the armrest 16, the body is lifted, moved forwards and carried to the position of getting on and off the chair. At the time of getting on the treatment chair, the armrest 16 is moved to the position in Figure (B) first inversely, the patient puts the hand or arm on the armrest 16 and applies the force backwards to the chair in the state and the armrest 16 is moved to the position in the Figure 1(A) in the state.