A machine tool includes a bed supported on a ground by supporting jigs, a table movable in an X-axis direction, a spindle head movable in a Y-axis direction, a quill provided to be movable in a Z-axis direction, a spindle supported by the quill to be rotatable about its axis, feed mechanisms for moving the table and the like in the axis directions, and a numerical controller controlling operation of the feed mechanisms, and the numerical controller is configured to calculate motion errors based on load values acting on the supporting jigs by a motion locus estimator, an influence coefficient storage, a motion error calculator, and a motion locus storage, generate a correction signal for compensating for the motion errors by a position corrector, and add the generated correction signals to a position control signal transmitted from a position generator to a position controller.