To provide a treatment chair that allows the aged and children to stably get in and off for dental treatment, etc.

A counter seat 1 is designed to be tilted forward by an angle of α degrees from a horizontal position, and particularly when the aged or a child gets on or off the chair, the counter seat 1 is tilted forward. When the aged or a child gets on the chair, he can be seated with his legs firmly set on the floor face 8, and when he is to get off the chair, his feet reach the floor face 8 while he is sitting, so that he can get in and off the chair with his feet in full contact with the floor face for safety and ease.