PROBLEM TO BE SOLVED: To provide an actuator, which has a compact shape allowing its use by wrapping around an object to be driven such as an existing endoscope and can perform efficient drive, and a control method of the actuator.SOLUTION: The actuator includes a tubular actuator body 1 having a plurality of pressure chambers 3 formed of an elastic body, and a pressure applying means 10 controlling charge/discharge of a fluid to/from a plurality of pressure chambers 3 to apply a predetermined pressure. In the actuator generating propulsion force by controlling pressures of a plurality of pressure chambers 3, the actuator body 1 has a single layer structure consisting of a circumference wall 5 having a substantially rectangular cross section, and includes a plurality of pressure chambers 3 formed by dividing the inside of the circumference wall 5 with elastic separation walls along the longitudinal direction of the actuator body 1.
