To provide an optical element which is used for a sensor such as CCD and CMOS and can inhibit ghost.

The optical element comprises an optically functional surface having a high surface accuracy and a flange formed on its outer circumference. In the optically functional surface having an optical surface diameter slightly larger than the effective diameter, a parting diameter of a mold is made larger than the optical surface diameter so that a parting line is placed outside the optical surface diameter and high surface accuracy at an effective diameter is ensured.