To provide a non-contact electric power supply device capable of properly detecting foreign objects existing on a surface of a housing for housing a coil.

A non-contact power supply system includes: a reader unit for optically reading an upper surface 121 of a housing 120 for housing a power transmission coil, which faces a power reception coil; and a foreign object detection part which detects foreign objects existing on the upper surface 121 of the housing 120. In the housing 120, an identification code 122 which is optically readable is disposed on the upper surface 121 of the housing 120. The foreign object detection part detects the foreign objects existing on the upper surface 121 of the housing 120 on the basis of the reading result of the identification code 122 which is read by the reader unit.