A medical apparatus includes: a main body apparatus switchable to a mode for outputting ultrasound vibration, mode for outputting high-frequency current, and mode for simultaneously outputting the ultrasound vibration and the high-frequency current; a probe for performing a first treatment with a first treatment portion; a first attaching and detaching portion including a first electric armature; an insertion portion including a second treatment portion, and configured to perform a second treatment, with a living tissue held between the first treatment portion and the second treatment portion; a second attaching and detaching portion including a second electric armature; a switch control section which switches the output of the high-frequency current to a monopolar output or a bipolar output according to a connection state between the first electric armature and the second electric armature.