A power consumption reducing device of a gap filler system includes a main module and a plurality of unit modules. The unit modules receive a signal from a terminal and determine whether the terminal is provided in beam coverage. The main module controls at least one unit module, one of which is a first unit module with beam coverage in which a terminal is provided from among a plurality of unit modules, to be turned on, and controls unit modules other than the turned-on unit module to be turned off.