A motor-operated valve comprising a valve stem having a valve plug; a valve body having a valve seat with which the valve plug is enabled to removably contact; a can fixed to the valve body; a rotor disposed coaxially in the can; a stator disposed around an outer circumferential surface of the can; a guide bush fixedly secured to the valve body and having an axial hollow portion in which the valve stem is permitted to slidably move; and a valve stem holder; wherein the valve stem is enabled to rotate integral with the valve stem holder and to move in the longitudinal direction thereof relative to the valve stem holder. The motor-operated valve is further provided with a flow rate adjusting feed screw mechanism which is constituted by a first stationary threaded portion and a first movable threaded portion; and with a rotation regulating feed screw mechanism which is constituted by a second stationary threaded portion and a second movable threaded portion. The pitch of the flow rate adjusting feed screw mechanism is made smaller than the pitch of the rotation regulating feed screw mechanism.