To provide a chair capable of serially controlling a seat height and a backrest part to suitable positions when a therapist or a user having a different leg length is to sit down.

In the chair having a seat part 1 held with a leg part 4 and a backrest part 2, the leg part 4 is divided into an upper leg part 41 and a lower leg part 42 and an elevating/lowering mechanism 5 is interposed between both the leg parts so that the seat part 1 and the backrest part 2 can be integrally elevated/lowered on the leg part 4. Then, the seat part 1 and the backrest part 2 are held with the upper leg part 41 and the seat part 1 and the backrest part 2 can be integrally elevated/lowered and controlled at the positions adaptive to the leg length or physique of the therapist or the user by this elevating/ lowering mechanism 5.