PURPOSE: To obtain the titled optical element having a convex lens with a simplified device inexpensively and easily by putting one surface of a planar optical element material on a specified planar forming die, compressing the opposite surface of the element material and extruding a part of the material into the shaping hole of the forming die.

CONSTITUTION: A planar optical element material 6 made of glass or a polymeric material is placed on a forming die 2 made of a material having higher m.p. than the material 6 and having ≥1 shaping hole 1, one surface of the material 6 is put on one surface of the forming die 2, a heater 5 is energized to heat and soften the material 6, then a pressing piston 3 is moved toward the forming die 2 to compress the material 6 which is pressed on the forming die 2, a part of the material is extruded into the shaping hole 1 and a spherical convex lens 7 is formed by surface tension. The material is then cooled and a planar optical element 8 having the convex lens 7 is obtained.