A high-frequency component in which a low-frequency-band transmission characteristic is not degraded even when impedance mismatching is generated by providing a SAW filter in a high-frequency-band circuit. The high-frequency component includes a diplexer having a high pass filter and a low pass filter connected in parallel to an antenna port, a high-frequency-band circuit serially connected to the high pass filter, and a low-frequency-band circuit serially connected to the low pass filter. A filter causing impedance mismatching is connected to the high-frequency-band circuit. The high pass filter includes a first series resonant circuit and a second series resonant circuit, and the resonance frequency of the first series resonant circuit is a trap frequency of a signal in the low-frequency band, and the resonance frequency of the second series resonant circuit is a trap frequency of undesired resonance generated in the transmission characteristic of the filter of the low-frequency-band side.