The present invention relates to an ultrasonic device for the treatment of arthritis, and more particularly, to an ultrasonic device for the treatment or prevention of degenerative arthritis, which is so structured that it generates ultrasonic waves with an intensity of 200-800 mW/cm2 and applies low-intensity ultrasonic energy of 100-400 mW/cm2 to cartilage cells deep in the skin's dermis. The inventive ultrasonic device comprises: a main control unit including an ultrasonic oscillation control unit allowing the generation of ultrasonic waves with a frequency of 0.1-5 MHz and low intensity of 200-800 mW/cm2; an ultrasonic generator for generating ultrasonic waves according to the control state of the main control unit; an ultrasonic vibrator that vibrates according to ultrasonic waves inputted from the ultrasonic generator; and a probe for transferring ultrasonic vibration to a joint to be treated. The ultrasonic device can induce the regeneration of cartilage tissue by the activation of cartilage tissue, and thus, can fundamentally treat degenerative arthritis.