Provided are a device and method for performing authentication in a wireless power transfer system. Provided is an authentication method in a wireless power transfer system including receiving a first packet including indication information on whether a target device supports an authentication function from the target device; transmitting, when the target device supports an authentication function, an authentication request message to the target device; receiving an authentication response message including a certificate on wireless charging from the target device in response to the authentication request message; and confirming authentication of the target device based on the authentication response message.