Provided is a lens unit. A second lens is provided with a flange surface section that surrounds a lens surface. An image-side flange surface has an image-side flange surface inner-circumferential section which is shaped like a ring-shaped groove, and also has a ring-shaped image-side flange surface outer-circumferential section formed to the outside of the inner-circumferential section. The image-side flange surface inner-outer circumferential section is coated with black ink. The image-side flange surface outer-circumferential section is provided with boss-shaped positioning surface at six equidistant locations along the outer circumference. Ejector pin contact sections are formed between adjacent positioning surface, and said contact sections contact the ejector pins at the time of separation from the mold during resin molding.