A power supply device (10) is provided with: a first memory unit (16) for storing a power supply pattern including placement position information for power supply coils (13); receiving units (14); and a first control unit (17) for supplying the power supply pattern to the power supply coils (13). A contactless power-receiving device (11) is provided with: a power-receiving coil (25); a second memory unit (28) for storing a power-receiving pattern; a comparison unit (29); and a second control unit (30). The second control unit (30) transmits the placement position information of the power-receiving pattern coinciding with the power supply pattern to the receiving units (14) of the power supply device (10) with a transmission unit (31) to identify the position of the contactless power-receiving device (11). In this manner, a contactless power transmission device capable of detecting whether the contactless power-receiving device (11) to which power is to be supplied is placed or not and the placement position is provided.
