An ultrasonic treatment head includes a head body and a cartridge. The head body includes: a body housing for supporting and protecting internal components and providing an interface for a user； a first actuator generating reciprocation on a first axis； a second actuator generating reciprocation on a second axis, and a stage pivoted about a fixed axis by the first actuator and the second actuator. The cartridge includes: a cartridge housing for keeping a transducer and liquid therein； a flat window disposed on the cartridge housing to transmit ultrasonic waves to a treatment area； a body coupler for coupling to the head body； an ultrasonic transducer generating ultrasonic waves in response to an operation signal input through the body coupler； and a fitting assembly moving the ultrasonic transducer on the flat window for in-plane scanning by a pivot motion, which is transmitted through the body coupler, of the stage.
