To provide a mechanism for preventing a danger when foreign matter is interposed in the lower part of a footrest in lowering a treatment chair.

This dental treatment chair has a backrest 3, a contour seat 4, a leg rest 5 and a footrest 6; and the backrest 3 and the leg rest 5 are tiltable interlocked with the movement of a font/rear movement block 43 provided in the lower part of the contour seat 4. The leg rest 5 is connected to the tip of a leg rest pusher (rotational) arm 44 extending frontward by the front/rear movement block 43, with a pin 53 to restrict the leg rest 5 from being separated from the leg rest pusher arm 44 and moving frontward. The footrest 6 is rotatably attached to the lower part of the leg rest 5 so that, when foreign matter is caught in the lower part of the footrest 6 in lowering the treatment chair, its front part rotationally turns upward and, when the rear part of the footrest moves downward, the rear part rotationally turns downward to stop the lowering operation of the dental treatment chair.