There is provided is a stereo headphone provided with a pair of earphones having a cartilage conduction unit, a sheath unit connected to the cartilage conduction unit, and a piezoelectric bimorph of a vibration source connected to the cartilage conduction unit covered by the sheath unit without making contact with the inner wall thereof. The cartilage conduction unit is an elastic body. The cartilage conduction unit is in contact with the entrance to the external auditory meatus and has a passage hole in communication with the external auditory meatus. The vibration source is supported by a thick portion on the tragus side at the periphery of the passage hole. In accordance with a more specific feature, the thick portion is provided. The outer shape of the sheath has a thickness in the direction of the earhole that is less than the thickness in the direction orthogonal thereto.