[Problem] To provide a headphone device that outputs an audio signal output from a playback device, such that the headphone device has a more compact housing while being capable of highly sensitive acoustic output of an audio signal having high sound quality, and is capable of consuming less power during highly sensitive acoustic output of an audio signal having high sound quality. [Solution] In a headphone device that outputs an input audio signal, the headphone device is provided with: a housing shaped with a hollow interior, said housing being provided with a projection on the front thereof, said projection being provided with a hole passing therethrough in the front-to-back direction; and a first driver unit and second driver unit each affixed to the inner wall of the housing, and each having a diaphragm that acoustically outputs the input audio signal. The first driver unit and the second driver unit have been given a parallel arrangement, such that the diaphragms thereof are in mutual opposition.