An ultrasonic therapy device comprises two bodies and two holding members. The body, at the inner face of which an oscillator is embedded, covers an affected area into which implant fixtures are embedded. The holding member which holds the body has a shape of a crown which covers teeth next to the affected area. Two teeth were removed from the affected area into which two implant fixtures are embedded. Each of the bodies covers the affected area between the teeth which is covered by the holding members so that the bodies are exactly fixed in an oral cavity. In this state, it is possible to accelerate osteogenesis around the implant fixtures by supplying an ultrasonic signal from an external driver to the oscillator.