A high-frequency coagulation apparatus according to the present invention comprises a controller for controlling supply of the fluid from a fluid supply section to a tubular body and controlling supply of the high-frequency electric current from a high-frequency electric current generation section to an electrode, wherein the controller has a first mode for supplying the high-frequency electric current from the high-frequency electric current generation section to the electrode and supplying the fluid from the fluid supply section to the tubular body, and a second mode for supplying the high-frequency electric current from the high-frequency electric current generation section to the electrode and interrupting supply of the fluid from the fluid supply section to the tubular body.