An angle measuring device includes: a signal extracting unit for extracting a signal that includes a first reflection wave and does not include a second reflection wave as a first demodulated signal and a signal that includes the second reflection wave and does not include the first reflection wave as a second demodulated signal from reception signals output from one or more reception antennas among a plurality of reception antennas; an elevation calculating unit for calculating an elevation of a target by performing monopulse angle measurement using a sum signal of the first demodulated signal and the second demodulated signal and a difference signal between the first demodulated signal and the second demodulated signal; and an azimuth calculating unit for calculating an azimuth of the target using reception signals output from the plurality of reception antennas.