The present disclosure provides a motor controller which can effectively stop a motor at a specific position in a short period of time, and can achieve an orientation operation more quickly. A motor controller for controlling a motor is configured to stop a rotary shaft rotating at a predetermined speed at a specified position in response to a stop command, and includes: a first time period calculator that calculates, based on a current speed, a target stop position and an acceleration at a time of positioning, a first time period that is to be taken by the rotary shaft to stop at the target stop position without change of a rotation direction of the rotary shaft; a second time period calculation unit that calculates, based on the current speed, the target stop position and the acceleration at the time of positioning, a second time period that is to be taken by the rotary shaft to stop at the target stop position after a temporary halt and rotation in an opposite direction subsequent to the temporary halt; a comparison unit that compares the first time period with the second period; and an orientated stop control unit that controls and stops, based on a result of comparison by the comparison unit, the motor such that the rotary shaft stops at the target stop position in a shorter period of time.