To prevent a dentist from using a start/stop switch in a vacuum apparatus by automatically driving the vacuum apparatus when an instrument for dental treatment is drawn out of an instrument holder.

This vacuum apparatus has a suction port arranged near the patient's oral cavity in a freely movable manner and the exhaust tube connected to the suction port 11 and the suction port is moved to the vicinity of the patient's oral cavity to suck and discharge floating matter scattered near the patient's oral cavity. When a densist draws an instrument for dental treatment out of an instrument holder, the vacuum apparatus is operated to suck and exclude contaminated air in the vicinity of the patient's oral cavity.