A digital signal receiver includes a reference signal generator for generating a first reference signal, a base band transform circuit for converting a first high-frequency signal with digital modulation into a base band signal with using the first reference signal, a frequency divider to divide the first reference signal, a frequency multiplier to multiply a frequency of a signal output from the frequency divider, and a digital demodulator to demodulate a signal output from the base band transform circuit with using the signal output from the frequency multiplier as a reference signal. The digital signal receiver consumes a small power since a small current flows in the frequency multiplier.