An optical device includes, for example, an optical fiber that guides light, a first holding member that holds the optical fiber, an optical element that functions by the light guided by the optical fiber being irradiated, and a second holding member that holds the optical element. The optical device further includes an optically coupled member elastically deformed by one end portion of the first holding member and one end portion of the second holding member being inserted to optically couple the optical fiber and the optical element by being elastically deformed.