Provided are a method, apparatus, and medium for measuring a distance using a radio frequency (RF) signal. The method of measuring a distance includes setting the transmitter power of an RF signal of a signal generating module to a minimum so as to measure the longest distance when no obstacle exists, measuring a distance between the signal generating module and a fixed module using the RF signal whose transmitter power is set to the minimum, if the measured distance between the signal generating module and the fixed module is available, determining that no obstacle exists therebetween, and if the measured distance is not available, determining that an obstacle exists therebetween, and determining the distance according to the result of the determination of existence of an obstacle.