A shock wave generating unit includes a housing and a disk in the housing. The disk includes a vibration plate, which corresponds to a shock wave transmission member covering a first opening of the housing and includes an insulating thin elastic plate and a thin metal plate. The insulating thin elastic plate, with one side corresponding to the shock wave transmission member and the opposite side provided with the thin metal plate, has a hollow portion for partially exposing the thin metal plate and forms an accommodating cavity together with the exposed portion of the thin metal plate and the shock wave transmission member. A shock wave transmission medium can circulate through the accommodating cavity via a channel in the housing and is in contact with the exposed portion of the thin metal plate to facilitate dissipation of the heat generated by the disk during operation.