A wireless power transmitter configured to wirelessly transmit power to an electronic device is provided. The wireless power transmitter includes a power transmission antenna including a plurality of patch antennas for wirelessly transmitting power, a sensor, and a processor, wherein the processor may be configured to create a first clutter map representing a reflection characteristic of an object positioned around the wireless power transmitter based on, at least, first data obtained by the sensor during a first period, store the first clutter map, compare a difference between the first clutter map and second data obtained by the sensor during a second period with data contained in the first clutter map, create a second clutter map corresponding to the second period based on a result of the comparison, determine a position of an organism using the second data and the second clutter map, and control the power transmission antenna such that a magnitude of the RF wave is less than a predetermined value based on the position of the organism.