Provided is a medical treatment device capable of eliminating inconvenience of manipulation in actual clinical use, and ensuring a visual field by introducing a curve in the vicinity of an electrode portion of an outer cylindrical tube. The medical treatment device has the following structure: an electrode portion including a first electrode and a second electrode arranged opposed to the first electrode, the electrode portion having a grasping function, a coagulating function, and a cutting function; an operation portion for executing drive of the respective functions of the first electrode and the second electrode; a shaft portion for connecting the electrode portion and the operation portion; a connector portion connectable to a microwave power source; and a conductive rod, which is provided inside the shaft portion, for transmitting a microwave to the electrode portion, the medical treatment device utilizing the microwave being configured to: hold body tissue between the first electrode and the second electrode; coagulate the body tissue by supplying the microwave to the first electrode and the second electrode; and cut the body tissue through a mutual action of the first electrode and the second electrode, in which the shaft portion and the electrode portion are connected to each other with a bent holder.