A wireless power receiver configured to wirelessly receive power from a wireless power transmitter, the wireless power receiver comprising: a reception coil configured to receive power having a first frequency band from the wireless power transmitter; a frequency detecting unit configured to detect if a frequency band of the power transmitted from the wireless power transmitter is the first frequency band, and to determine the frequency band of the power transmitted from the wireless power transmitter as a second frequency band if the detected frequency band is out of the first frequency band, the first frequency band being lower than the second frequency band; and an inductance varying unit configured to change an inductance of the reception coil if the detected frequency band is out of the first frequency band, wherein the inductance varying unit is configured to decrease the inductance of the reception coil such that a used frequency band of the wireless power receiver is matched to the second frequency band if the frequency detecting unit determines that the frequency band of the power transmitted from the wireless power transmitter is the second frequency band, characterized in that the frequency detecting unit is configured to send a ping signal to the wireless power transmitter and to detect the frequency band based on a response signal to the ping signal through in-band communication, wherein the frequency detecting unit is configured to determine the frequency band of the power transmitted from the wireless power transmitter through out-of-band communication if the frequency detecting unit does not receive the response signal to the ping signal. a reception coil configured to receive power having a first frequency band from the wireless power transmitter; a frequency detecting unit configured to detect if a frequency band of the power transmitted from the wireless power transmitter is the first frequency band, and to determine the frequency band of the power transmitted from the wireless power transmitter as a second frequency band if the detected frequency band is out of the first frequency band, the first frequency band being lower than the second frequency band; and an inductance varying unit configured to change an inductance of the reception coil if the detected frequency band is out of the first frequency band, wherein the inductance varying unit is configured to decrease the inductance of the reception coil such that a used frequency band of the wireless power receiver is matched to the second frequency band if the frequency detecting unit determines that the frequency band of the power transmitted from the wireless power transmitter is the second frequency band, characterized in that the frequency detecting unit is configured to send a ping signal to the wireless power transmitter and to detect the frequency band based on a response signal to the ping signal through in-band communication, wherein the frequency detecting unit is configured to determine the frequency band of the power transmitted from the wireless power transmitter through out-of-band communication if the frequency detecting unit does not receive the response signal to the ping signal.