A direct conversion radio apparatus comprises a local oscillator which generates a high-frequency signal of almost the same frequency as that of a signal to be received, a modulator which modulates the high-frequency signal generated from the local oscillator in carrier sensing, mixers which frequency-convert a received signal into a baseband frequency by using the high-frequency signal modulated by the modulator in carrier sensing, low-pass filters which limit bands of baseband signals extracted by frequency-converting by the mixers, and a baseband circuit which controls the frequency of the high-frequency signal generated from the local oscillator and also performs carrier sensing by amplitude of the baseband signals output from the low-pass filters.