An electric power-steering apparatus, comprising: a cylindrical steering column (1, 1b) that is supported by a vehicle body; a steering shaft (2, 2b) that is supported on the inside of the steering column (1, 1b) so as to be able to rotate freely, and that is rotated by a steering wheel that is fastened to the rear end section thereof; electrical components that are used for applying auxiliary power in the same direction as the force applied from the steering wheel to the steering shaft (2, 2b) or to a member that displaces as the steering shaft (2, 2b) rotates; a connector (18, 18a, 26, 27) for supplying electric power to the electrical components; and a housing that is fastened to the front end section of the steering column (1, 1b) and comprises; a worm wheel housing section that has an approximate circular disk shape, that is arranged so as to be concentric with the steering column (1, 1b), and that houses a worm wheel inside thereof; and a torque sensor housing section that is provided adjacent to the rear side of the worm wheel housing section, that has a smaller diameter than the worm wheel housing section and that houses a torque sensor inside thereof, characterized in that a substantially flat shaped protective wall section (21, 21a) is provided on the bottom surface of the steering column (1, 1b) or a bottom surface of the worm wheel housing section and extends downward when assembled in the vehicle, and assuming that the electric power-steering apparatus is placed on a flat plane, a bottom end section of the protective wall section (21, 21a) comes in contact with the flat plane, and the connector (18, 18a, 26, 27) is installed in a portion that is located below the steering column (1, 1b) or the torque sensor housing section when assembled in the vehicle, and that is above and separated from the flat plane assuming that the electric power-steering apparatus is placed on the flat plane with a bottom surface of the steering column (1, 1b) facing downward when assembled in the vehicle. a cylindrical steering column (1, 1b) that is supported by a vehicle body; a steering shaft (2, 2b) that is supported on the inside of the steering column (1, 1b) so as to be able to rotate freely, and that is rotated by a steering wheel that is fastened to the rear end section thereof; electrical components that are used for applying auxiliary power in the same direction as the force applied from the steering wheel to the steering shaft (2, 2b) or to a member that displaces as the steering shaft (2, 2b) rotates; a connector (18, 18a, 26, 27) for supplying electric power to the electrical components; and a housing that is fastened to the front end section of the steering column (1, 1b) and comprises; a worm wheel housing section that has an approximate circular disk shape, that is arranged so as to be concentric with the steering column (1, 1b), and that houses a worm wheel inside thereof; and a torque sensor housing section that is provided adjacent to the rear side of the worm wheel housing section, that has a smaller diameter than the worm wheel housing section and that houses a torque sensor inside thereof, characterized in that a substantially flat shaped protective wall section (21, 21a) is provided on the bottom surface of the steering column (1, 1b) or a bottom surface of the worm wheel housing section and extends downward when assembled in the vehicle, and assuming that the electric power-steering apparatus is placed on a flat plane, a bottom end section of the protective wall section (21, 21a) comes in contact with the flat plane, and the connector (18, 18a, 26, 27) is installed in a portion that is located below the steering column (1, 1b) or the torque sensor housing section when assembled in the vehicle, and that is above and separated from the flat plane assuming that the electric power-steering apparatus is placed on the flat plane with a bottom surface of the steering column (1, 1b) facing downward when assembled in the vehicle.