An energy-regenerating damper including a piston provided with a housing fitted inside a cylinder so as to be able to slide against the inner surface of the cylinder, a stator contained in/fixed to the inside of the housing, a rotor supported so as to be able to rotate inside the stator, and damping valves provided at the top and bottom ends of the housing. The housing includes an upper half and a lower half fastened together by bolts, and a damper rod is fixed to the top end of the upper half. The upper half and the lower half each contain a bearing for supporting the rotor. A plurality of orifices through which a hydraulic oil circulates are drilled towards the outsides of the upper half and lower half, and circulation holes through which the hydraulic oil circulates are drilled towards the insides of the upper half and lower half.