A microphone unit (1) is disposed in the inside of a first housing (51) of a voice input apparatus. The microphone unit (1) includes: a second housing (11); a diaphragm (122) which is disposed in the inside of the second housing (11); and an electric circuit portion (12, 13, 14) which processes an electric signal that is generated based on a vibration of the diaphragm (122). In the voice input apparatus, a first sound guide space (513) which guides a sound outside the first housing (51) to a first surface (122a) of the diaphragm (122) and a second sound guide space (514) which guides a sound outside the first housing (51) to a second surface (122b) of the diaphragm (122) are formed. The electric circuit portion (12, 13, 14) is disposed in either one of the first sound guide space (513) and the second sound guide space (514); and an acoustic resistance portion (52) which adjusts at least one of a frequency characteristic of the first sound guide space (513) and a frequency characteristic of the second sound guide space (514) is formed.