A multiband mobile unit communication apparatus is disclosed which comprises: an antenna for receiving L FRQ bands of M radio wave SIGs modulated by N modulating methods, M>L, M>N, N≧L; a frequency synthesizer for generating a LO SIG; an IF SIG generation CKT for generating M IF SIGs using the LO SIG, the FRQ synthesizer generating the LO SIG such that the M IF SIGs have the same intermediate FRQ; a SW CKT for selectively outputting N IF SIGs modulated by the N modulating methods respectively out of the M IF SIGs; N filters for filtering outputs of N IF SIGs from the SW CKT and outputting N filtered IF SIGs respectively; a SW responsive to a SW CONT signal for selectively outputting one of the N filtered IF SIGs; and a quadrature demodulator for quadrature-demodulating one of N filtered IF SIGs and outputting baseband SIG. Different frequency bands of received signals are converted into IF SIGs having the same intermediate frequency. Moreover, different frequency bands of received signals which are modulated by the same method are filtered by the same IF filter.