PROBLEM TO BE SOLVED: To provide an optical device, while being down-sized, capable of preventing damage of an electric wire connected to a light adjusting device, facilitating the connection of the electric wire and further securing connection strength of the electric wire.SOLUTION: The optical device includes: the light adjusting device having an objective optical system and a drive unit 57 for driving the objective optical system a cylindrical first frame 21 in which the light adjusting device is provided, and that has a first convex part 21b having a retraction space for the objective optical system and has a protrusion 21t extending rearward from a base end 21bq of the first convex part 21b an electric wire 60, the tip end 60s of which is fixed to the protrusion 21t and a lead wire 61 that is provided in the first frame 21 and electrically connects the tip end 60s of the electric wire 60 to the drive unit 57.
