A dental treatment device in which attenuation of a laser beam is not liable to occur is provided. This dental treatment device (1) is provided with a vibration unit (2) for vibrating by a vibrator (21) that generates ultrasonic vibrations a chip unit (3) connected to the vibration unit (2) and through which ultrasonic vibrations are transmitted a flow channel (4) for discharging an antimicrobial agent from the chip unit (3) and an optical system (5) for irradiating a laser beam for photo decomposing the antimicrobial agent from the chip unit (3) the optical system (5) having an optical path separate from the flow channel (4).
