To permit a doctor to easily perform explanation to a patient in the all cases of a consultant position where the back of a dental chair is erected and of a medical treatment position state where the dental chair is in a supine state while confirming dental treatment information of the patient by arranging a liquid crystal monitor and a viewer, etc., at an intermediate position between a doctor table and the dental chair where the patient is seated.

The dental chair is provided with an arm 2 pivotally supported by a base 1, a vertical box 3 which is supported by the arm 2 at a lower end part and where electric units are incorporated, the doctor table 5 supported by a support rod 4 at one end in the upper part of the box 3 and the monitor 9 at the other end in the upper part of the box 3. The monitor is freely vertically movable, freely movable in a horizontal direction and freely rotatable in the vertical direction.