Disclosed is a wireless power transmitting device and method, the wireless power transmitting device including, in response to detection of a power receiver within a predetermined separation distance from a charging pad, a controller configured to generate a magnetic field through a transmission coil with a multilayer structure in which a plurality of coil layers of different sizes are stacked, and a power transmitter configured to wirelessly transmit, to a reception coil of the power receiver, a power signal generated using magnetic fields generated by the plurality of coil layers.