PURPOSE: To provide the dental treatment unit which reduces the burden of a dentist and an assistant or the like with high safety and more improves safety by decreasing the number if switches or wirings or the like while using a means to use one circuit for plural function at the same time.

CONSTITUTION: Concerning the dental treatmtent unit provided with a treatment chair to raise a back rest and to elevate a seat plate, this unit is constituted so as to stop the treatment chair in emergency even when any operation switch is depressed at the time of driving for raising the treatment chair or elevating the seat plate. Otherwise, the back rest or the seat plate is provided with a maintenance switch, and when any obstacle touches this switch with pressure at the time of driving, an alarm is sounded, the treatment chair is stopped, and when any operation switch of an operation part is depressed, the alarm is cancelled, and the chair is returned to the original position just to a certain extent. It is also preferable to constitute the unit so as to cancel the alarm when the factor to cause the operation of the maintenance switch is removed.