A contactless power transmission device which transmits electric power in a contactless way includes: a power transmission section which transmits electric power using a primary coil; a power receiving section which is provided in a radio communication device and receives electric power using a secondary coil that is electromagnetically coupled with the primary coil; a housing which shields an electromagnetic wave, in which the power transmission section is provided, and which forms a closed space where the radio communication device is housed; and a housing antenna section which is provided in the housing and transmits a first communication signal to the outside of the housing, or transmits a second communication signal to the inside of the housing, the first communication signal being emitted from the radio communication device housed inside the housing, the second communication signal being emitted from the radio communication device housed outside the housing.