Disclosed herein is a dielectric waveguide antenna including: a dielectric waveguide transmitting a signal applied from a power feeder; a dielectric waveguide radiator radiating the signal transmitted from the dielectric waveguide to the air through a first aperture; and a matching unit formed in a portion of the dielectric waveguide and controlling a serial reactance and a parallel reactance to thereby perform impedance matching between the dielectric waveguide radiator and the air, in order to reduce reflection generated in the first aperture during the radiation of the signal through the first aperture. Reflection in the aperture is reduced through the matching unit having various structures, thereby making it possible to improve characteristics of the dielectric waveguide antenna.