A surface light source includes: a light guide plate having an upper surface and a lower surface located opposite the upper surface, and comprising at least one through hole extending from the upper surface to the lower surface; a wiring substrate located on a lower surface side of the light guide plate and comprising a wiring layer; and at least one light source comprising a light-emitting element electrically connected to the wiring layer of the wiring substrate. The light source is located inside the through hole. The upper surface of the light guide plate has a first region including a plurality of protruding portions or depressed portions. In a plan view, a proportion of an area of the protruding portions or depressed portions per unit area of the first region increases among concentric parts of the first region in the direction away from the light source.