A wireless power transmission method of a wireless power transmitter , the wireless power transmission method comprising: performing a foreign object detection procedure based on a quality factor value before power transmission; and performing a foreign object detection procedure based on path loss during the power transmission, wherein the foreign object detection procedure based on the quality factor value comprises: storing a measured quality factor value of a resonant circuit ; receiving a foreign object detection status packet comprising a reference quality factor value; determining a quality factor threshold value based on the reference quality factor value; and comparing the measured quality factor value with the quality factor threshold value to determine whether the foreign object is present, wherein the foreign object detection procedure based on the path loss comprises: calculating the path loss based on a transmit power strength and a receive power strength; and comparing the calculated path loss with a path loss threshold value to determine whether the foreign object is present, wherein the path loss threshold value is dynamically determined, and characterised by if determining that the foreign object is not present through the foreign object detection procedure based on the quality factor value, the foreign object detection procedure based on the path loss is performed. performing a foreign object detection procedure based on a quality factor value before power transmission; and performing a foreign object detection procedure based on path loss during the power transmission, wherein the foreign object detection procedure based on the quality factor value comprises: storing a measured quality factor value of a resonant circuit ; receiving a foreign object detection status packet comprising a reference quality factor value; determining a quality factor threshold value based on the reference quality factor value; and comparing the measured quality factor value with the quality factor threshold value to determine whether the foreign object is present, storing a measured quality factor value of a resonant circuit ; receiving a foreign object detection status packet comprising a reference quality factor value; determining a quality factor threshold value based on the reference quality factor value; and comparing the measured quality factor value with the quality factor threshold value to determine whether the foreign object is present, wherein the foreign object detection procedure based on the path loss comprises: calculating the path loss based on a transmit power strength and a receive power strength; and comparing the calculated path loss with a path loss threshold value to determine whether the foreign object is present, calculating the path loss based on a transmit power strength and a receive power strength; and comparing the calculated path loss with a path loss threshold value to determine whether the foreign object is present, wherein the path loss threshold value is dynamically determined, and characterised by if determining that the foreign object is not present through the foreign object detection procedure based on the quality factor value, the foreign object detection procedure based on the path loss is performed. <EOS>