A flexible printed wiring board according to one embodiment of the present invention is provided with: an insulating base film; a conductive pattern which is laminated on at least the back surface ofthe base film and comprises a spiral coil pattern; and a plating layer which is laminated on the back surface of the conductive pattern and is formed of a ferromagnetic body. The conductive pattern may additionally comprise a coil core pattern that is formed inside the innermost turn of the coil pattern.