An electric power steering apparatus comprising: a steering shaft through which a steering torque is transmitted; an electric motor for transmitting a steering assist force to the steering shaft via a reduction mechanism in a reduction gearbox; a control unit including a control substrate on which a control circuit for drive-controlling the electric motor is mounted; a plurality of sensor terminals (15c-15f) connected to a torque sensor included in the reduction gearbox and protruding from an outer circumference of the reduction gearbox; a plurality of through holes arranged at the control substrate; and a plurality of connection terminals (28a-28d) electrically connecting the plurality of sensor terminals (15c-15f) and the plurality of through holes, respectively, wherein the control unit includes a frame of synthetic resin for holding the control substrate, characterized in that the frame of synthetic resin partially insert-molds the plurality of connection terminals (28a-28d) with one ends of the plurality of connection terminals (28a-28d) connected to the plurality of through holes, and the other ends of the plurality of connection terminals (28a-28d) protruding at the outside of the frame of synthetic resin, wherein the frame of synthetic resin includes a sensor terminal holding portion having guide openings arranged at positions opposing open ends of the plurality of sensor terminals (15c-15f), wherein the control unit is mounted on the reduction gearbox with the open ends of the plurality of sensor terminals (15c-15f) being inserted into the guide openings, and the other ends of the plurality of connection terminals (28a-28d) and the open ends of the plurality of sensor terminals (15c-15f) are respectively connected by soldering together. a steering shaft through which a steering torque is transmitted; an electric motor for transmitting a steering assist force to the steering shaft via a reduction mechanism in a reduction gearbox; a control unit including a control substrate on which a control circuit for drive-controlling the electric motor is mounted; a plurality of sensor terminals (15c-15f) connected to a torque sensor included in the reduction gearbox and protruding from an outer circumference of the reduction gearbox; a plurality of through holes arranged at the control substrate; and a plurality of connection terminals (28a-28d) electrically connecting the plurality of sensor terminals (15c-15f) and the plurality of through holes, respectively, wherein the control unit includes a frame of synthetic resin for holding the control substrate, characterized in that the frame of synthetic resin partially insert-molds the plurality of connection terminals (28a-28d) with one ends of the plurality of connection terminals (28a-28d) connected to the plurality of through holes, and the other ends of the plurality of connection terminals (28a-28d) protruding at the outside of the frame of synthetic resin, wherein the frame of synthetic resin includes a sensor terminal holding portion having guide openings arranged at positions opposing open ends of the plurality of sensor terminals (15c-15f), wherein the control unit is mounted on the reduction gearbox with the open ends of the plurality of sensor terminals (15c-15f) being inserted into the guide openings, and the other ends of the plurality of connection terminals (28a-28d) and the open ends of the plurality of sensor terminals (15c-15f) are respectively connected by soldering together.