A wireless power transmitting apparatus for detecting a foreign object, the apparatus comprising: a primary core block adapted for being coupled with a secondary core block equipped in a wireless power receiving apparatus through magnetic induction or magnetic resonance and configured for transmitting wireless power to the wireless power receiving apparatus (150-n) by the magnetic induction or the magnetic resonance; an electric driving unit connected to the primary core block and configured for applying an alternating current, AC, signal required for the primary core block to transmit the wireless power; and a control unit being connected to the electric driving unit and configured for generating a control signal for controlling the AC signal, wherein the control unit is arranged to apply a control signal to the electric driving unit and to check whether a signal strength packet is received in a time window from the wireless power receiving apparatus; wherein when the signal strength packet is received in the time window, the control unit is arranged to check whether an identification packet and configuration information are received from the wireless power receiving apparatus; wherein, when the identification packet and the configuration information are received, the control unit is arranged to check whether a power control packet is received from the wireless power receiving apparatus; wherein, when the power control packet is received, the wireless power transmitting apparatus is configured to perform control of wireless power transmission based on the power control packet to allow a control unit of the wireless power receiving apparatus to receive required power; wherein when the identification packet and the configuration information are received, the control unit is arranged to check whether a foreign object state packet is received from the wireless power receiving apparatus; wherein the control unit is configured to perform foreign object detection if the foreign object state packet is received from the wireless power receiving apparatus; and wherein the control unit is configured to measure an initial transmission power transmitted from the primary core block and to perform the foreign object detection on the basis of the initial transmission power, after it is determined by the control unit that an initial voltage of an output terminal in the wireless power receiving apparatus configured to be connected to an external load belongs to a range of a reference voltage by receiving from the wireless power receiving apparatus the foreign object state packet indicating start of the foreign object detection. a primary core block adapted for being coupled with a secondary core block equipped in a wireless power receiving apparatus through magnetic induction or magnetic resonance and configured for transmitting wireless power to the wireless power receiving apparatus (150-n) by the magnetic induction or the magnetic resonance; an electric driving unit connected to the primary core block and configured for applying an alternating current, AC, signal required for the primary core block to transmit the wireless power; and a control unit being connected to the electric driving unit and configured for generating a control signal for controlling the AC signal, wherein the control unit is arranged to apply a control signal to the electric driving unit and to check whether a signal strength packet is received in a time window from the wireless power receiving apparatus; wherein when the signal strength packet is received in the time window, the control unit is arranged to check whether an identification packet and configuration information are received from the wireless power receiving apparatus; wherein, when the identification packet and the configuration information are received, the control unit is arranged to check whether a power control packet is received from the wireless power receiving apparatus; wherein, when the power control packet is received, the wireless power transmitting apparatus is configured to perform control of wireless power transmission based on the power control packet to allow a control unit of the wireless power receiving apparatus to receive required power; wherein when the identification packet and the configuration information are received, the control unit is arranged to check whether a foreign object state packet is received from the wireless power receiving apparatus; wherein the control unit is configured to perform foreign object detection if the foreign object state packet is received from the wireless power receiving apparatus; and wherein the control unit is configured to measure an initial transmission power transmitted from the primary core block and to perform the foreign object detection on the basis of the initial transmission power, after it is determined by the control unit that an initial voltage of an output terminal in the wireless power receiving apparatus configured to be connected to an external load belongs to a range of a reference voltage by receiving from the wireless power receiving apparatus the foreign object state packet indicating start of the foreign object detection.