To provide a radar apparatus capable of shortening the minimum detection distance at low cost, although the size is small.

This radar apparatus includes a modulation signal generating circuit that generates a baseband signal STB; a carrier wave generating circuit 4 that generates a carrier wave Sc; a modulation circuit 6 that modulates the carrier wave Sc, using the baseband signal STB; a mixer circuit 12 that extracts the baseband signal SRB from the high-frequency signal SRR; and a detection signal generating circuit 15 that generates a detection signal Sd, which can be used to measure the distance to a vehicle 21, based on the baseband signal SRB and the baseband signal SRB reflected by the vehicle 21 and extracted by the mixer circuit 12. The modulation signal generating circuit includes a sine-wave signal generating circuit 2 that generates a sine-wave signal SSI and a pulse signal generating circuit 3 that generates a baseband signal STB, by converting the sine wave signal SSI into a pulse signal, using a step-recovery diode.