An automatic transmission includes first and second clutches disposed adjacent, wherein each of the first and second clutches includes a friction plate; a clutch drum in spline engagement with the friction plate; a piston that with the clutch drum forms a hydraulic oil chamber therebetween; a return spring that biases the piston toward the hydraulic oil chamber side; and a cancel plate that is disposed on a side opposite the hydraulic oil chamber of the piston to form a cancel oil chamber that cancels outs a centrifugal hydraulic pressure that acts on the hydraulic oil chamber, and that receives a reaction force of the return spring.