In a medical treatment device, an operation member is placed at a portion near a head of a housing, and a selection member is placed nearer to a base of the housing than the operation member. Operation for causing the medical treatment device to function is input with the operation member. A control unit is capable of causing the medical treatment device to function in a plurality of modes. The control unit selects one of the modes as a mode in which the medical treatment device is caused to function based on a detection result of an operating state of the selection member.
