A wireless power transmission device comprising: a wireless charging circuit comprising a transmission coil ; and one or more processors (480; 620) operatively connected with the wireless charging circuit, wherein the one or more processors are configured to: receive, from a wireless power reception device , a first signal to request wireless charging information related to the wireless power transmission device using the wireless charging circuit while a power is transmitted via the transmission coil for wirelessly charging the wireless power reception device , in response to the receiving of the first signal, transmit, through the wireless charging circuit to the wireless power reception device , first charging information comprising information relating to a voltage, a current or a power that is supportable by the wireless power transmission device , receive, from the wireless power reception device , a second signal including second charging information relating to the voltage, the current or the power using the wireless charging circuit , based at least in part on the second signal, control the wireless charging circuit to change a voltage, a current or a power to be applied to the transmission coil . a wireless charging circuit comprising a transmission coil ; and one or more processors (480; 620) operatively connected with the wireless charging circuit, wherein the one or more processors are configured to: receive, from a wireless power reception device , a first signal to request wireless charging information related to the wireless power transmission device using the wireless charging circuit while a power is transmitted via the transmission coil for wirelessly charging the wireless power reception device , in response to the receiving of the first signal, transmit, through the wireless charging circuit to the wireless power reception device , first charging information comprising information relating to a voltage, a current or a power that is supportable by the wireless power transmission device , receive, from the wireless power reception device , a second signal including second charging information relating to the voltage, the current or the power using the wireless charging circuit , based at least in part on the second signal, control the wireless charging circuit to change a voltage, a current or a power to be applied to the transmission coil . receive, from a wireless power reception device , a first signal to request wireless charging information related to the wireless power transmission device using the wireless charging circuit while a power is transmitted via the transmission coil for wirelessly charging the wireless power reception device , in response to the receiving of the first signal, transmit, through the wireless charging circuit to the wireless power reception device , first charging information comprising information relating to a voltage, a current or a power that is supportable by the wireless power transmission device , receive, from the wireless power reception device , a second signal including second charging information relating to the voltage, the current or the power using the wireless charging circuit , based at least in part on the second signal, control the wireless charging circuit to change a voltage, a current or a power to be applied to the transmission coil . <EOS>