Methods and apparatuses for performing wireless charging are disclosed. One of the disclosed apparatuses is a wireless power receiver which can receive charging power from a wireless power transmitter. When the wireless power receiver receives, through a power receiving circuit, from a wireless power transmitter, a first power for initiating a communication unit; establishes a communication connection with the wireless power transmitter while receiving the first power; performs, by the communication unit, communication with the wireless power transmitter; receives, through the power receiving circuit, from the wireless power transmitter, a second power for charging; transmits, by the communication unit, to the wireless power transmitter, a message indicating a mode transition of the communication unit; terminates the communication with the wireless power transmitter; performs the mode transition for a time period while receiving the second power; and resumes the communication with the wireless power transmitter, after performing the mode transition.