A wireless power-transmitting system which wirelessly transmits electric power by making a power-transmitting coil and a power-receiving coil face each other includes: a cover which is slidable between a closing position at which the cover covers an area above a facing surface of the power-transmitting coil and an open position at which the cover is retracted from the area above the facing surface; and a hook member which makes a foreign object placed on the cover move together with the cover sliding from the closing position to the open position.