To provide an optical modulation element or the like, of which the manufacturing cost can be suppressed.

The optical modulation element comprises a first transparent member 11 having a first transparent electrode 21; a microprism member 24 arranged on the first transparent electrode and having lipophilicity; a transparent oil film 25 formed on the surface of the microprism member and has a refractive index substantially equal to that of the neighboring materials on the surface; a second transparent member 12, having a second transparent electrode 22 arranged with a predetermined space with the oil film; and a transparent electrolyte solution 26, which is filled in between the second transparent electrode and the oil film, electrically insulated with the first transparent electrode, and has a refractive index that is different from that of the material of the microprism member.