A light emitting device includes a light emitting element emitting light from a top surface and a side surface, and a light flux controlling member controlling distribution of light emitted therefrom. The light flux controlling member includes a rear surface, an incidence surface, and an emission surface. When opening diameter of recess is φ, maximum length of the light emitting element in plan view is L, and thickness of the light emitting element is t, diameter φ is equal to or more than twice a distance from a point where illuminance of light emitted from the side surface thereof to reach the substrate is maximum in illuminance distribution on the substrate to central axis of the light flux controlling member, and is less than “L+12t.”