A high-frequency module enabling sufficient attenuation over a wide frequency range outside of a passband includes a triplexer including a combination of an LPF, a BPF, and HPFs arranged to demultiplex a signal input from a common terminal into a first communication signal, a second communication signal, and a third communication signal in different frequency bands, and to output the first, second, and third communication signals from individual terminals. The individual terminals of the triplexer are connected to respective baluns. The baluns are configured such that the respective passbands of the baluns overlap the respective frequency bands of the communication signals and the respective passbands of the triplexer, and the attenuation of the baluns at the attenuation poles of the triplexer is −3 dB or greater. This configuration provides high attenuation in the rebound bands of the attenuation poles.