The present invention relates to an optical element including an optical surface, a tapered part located on an outer peripheral side of the optical surface and having a normal line of which a direction heading to an outside of the optical element from an inside thereof, faces an optical axis side, and a side surface part located on an outer peripheral side of the tapered part, in which when a distance in a straight line vertical to an optical axis of from an end point on the optical axis side of the tapered part to the side surface part is denoted by A and a height of the tapered part based on the straight line is defined by B, in a cross section including the optical axis and passing through the tapered part, B/A is larger than 0.2.