Lens manufacturing method and lens

A lens manufacturing method comprising:

• filling a gap between a lower mold and an upper mold with a resin material that is energy-beam curable, the lower mold including a concave portion and an annular recess around the concave portion on an upper face of the lower mold, the upper mold being disposed with the gap between the concave portion and the upper mold;
• and
• curing the resin material with which the gap is filled, while irradiating the resin material with an energy beam through the lower mold or the upper mold, to mold a lens as a cured object of the resin material, the lens including a lens surface and a flange expanding radially from a circumference of the lens surface, wherein
• the filling includes filling the gap with the resin material until a liquid surface of the resin material reaches an inner circumferential wall portion of the annular recess open upward, the inner circumferential wall portion corresponding to an outer circumferential wall portion of the flange.