A position controller includes: an oil temperature acquisition unit that acquires information on an oil temperature of a hydraulic actuator; a position acquisition unit that acquires an actual value of an operation position of an object; a position control unit that calculates an operation command value for a control valve of the hydraulic actuator by closed-loop control so as to reduce a deviation between a target value of the operation position of the object and the actual value; and a gain setting unit that changes at least one gain of the closed-loop control so that sensitivity of the closed-loop control increases as the oil temperature decreases.