A method for manufacturing a planar light source includes preparing a wiring substrate including a first region that includes a light source placement section; disposing a light-reflective member in the first region of the wiring substrate; preparing a light guide plate including a first major surface, a second major surface opposite to the first major surface, and a first hole extending from the first major surface to the second major surface; disposing a light source on the light-reflective member at the light source placement section; disposing the light guide plate on the wiring substrate to cause the wiring substrate and the second major surface of the light guide plate to face each other to cause the light source to be positioned in the first hole; and disposing a first light-transmitting member in the first hole.