PURPOSE: To maintain a position relation between a containing chamber and an inner circumferential surface in a constant state by a method wherein a guide shaft in a circular shape in cross section at least a part of which is inserted in a containing hole and to the outer peripheral surface of which the side on the inner circumferential side of a vane makes contact is arranged at the end part of a casing.

CONSTITUTION: A rotary type actuator A comprises a casing 1; a rotor 2; and a plurality of vanes 3. In which case, the casing 1 consists of a body 11 and a cover body 12. Further, the rotor 2 has one end part rotatably extending through the cover body 12 and the other end part rotatably inserted in a containing chamber 13. Further, a containing hole 21 extending over an axis L2 is formed in an end part entering the containing chamber 13. A plurality of vane grooves 22 extending therethrough are formed radially centering around the axis L2 and the vane 3 is slidably inserted in each vane groove 22. A guide shaft part 14 is formed on the bottom of the containing chamber 13, and rotatably inserted in the containing hole 21.