A treatment device includes a probe for acquiring an image of a target using ultrasonic waves, a needle guide provided in the probe, a needle movable along the needle guide, a measurement unit for sensing a movement distance of the needle in a noncontact fashion, and a controller for calculating the movement distance of the needle based on a value measured by the measurement unit. The treatment device may further include a needle sensing unit to determine whether the needle has reached a reference position. The measurement unit is driven based on the determination of the needle sensing unit for measuring the movement distance of the needle.
