There are provided an optical receptacle having an optical fiber including a first portion on another end surface side, a third portion on one end surface side, and a second portion between the first portion and the third portion; a core diameter at the first portion is smaller than the core diameter at the third portion; the core diameter at the second portion increases from the first portion side toward the third portion side; a first elastic member is provided between the optical fiber and an inner wall of a through-hole; a holder holds the another end surface side of a fiber stub; and the sleeve holds the one end surface side of the fiber stub.