A planar light-emitting device includes a light source element and a light guide plate. The light source element is configured to emit light. The light guide plate has a housing hole, a light-emitting face and a light reflecting face. The housing hole houses the light source element. The light reflecting face is formed along a side end portion of the light guide plate. The light reflecting face has an inclined portion that is located next to the housing hole in a first direction of the light guide plate and a flat portion that is located next to the inclined portion in a second direction that is perpendicular to the first direction. The inclined portion has an inclination angle with respect to the flat portion such that the light reflected on the inclined portion is prevented from returning the housing hole.