To provide an excellent sound output device which is worn on an ear of a user and used. The sound output device includes a sound generation part and a holding part that has an opening portion and holds the sound generation part in the vicinity of an entrance of an ear canal of a user. The holding part includes a ring body having the opening portion, and a housing of the sound generation part is integrated with a part of the ring body. The sound generation part includes a sound generation element having a dynamic type driver, and has a hollow exhaust part joining with a rear surface of the housing of the sound generation part. The exhaust part extends from a rear surface side of the housing across an intertragic notch and has an exhaust hole outside an auricle.