A light absorber includes an insulating substrate; a reflective layer that is provided on the insulating substrate, that is composed of a metal, and that has conductivity; a conductive pattern that is disposed on the reflective layer and that has defined therein at least one first opening; a nano-antenna that is disposed on the reflective layer and that vertically overlaps the at least one first opening; and an insulating pattern having a first portion that is interposed between the reflective layer and the conductive pattern and having a second portion that is interposed between and completely fills a vertical space between the reflective layer and the nano-antenna so that the reflective layer, the conductive pattern, and the nano-antenna are electrically insulated from each other.