Provided is a medical apparatus including a treatment tool having a distal-end treatment section, a joint section, and a flexible elongated body section in this order from the distal end; a driver that is connected to the base end of the body section and that supplies a driving force to the joint section; an operation input unit that is a separate unit from the treatment tool and the driver and that has a main body holdable with one hand of an operator and an operable member disposed at a position where it is operable using a finger of the one hand holding the main body; and a controller that controls the driver in accordance with an operation command input to the operation input unit.