A light emitting device , comprising: a substrate including: a base member including a front surface extending in a first direction as a longer direction and a second direction as a shorter direction, a rear sur-face located opposite to the front surface , a bottom surface adjacent to and perpendicular to the front surface , and a top surface located opposite to the bottom surface , and a first wiring portion located on the front surface , and a second wiring portion located on the rear surface ; a plurality of light emitting elements including a first light emitting element electrically connected with the first wiring portion and placed on the first wiring portion ; a first reflective member covering lateral surfaces of the plurality of light emitting elements and the front surface of the base member ; and a light-transmissive member disposed over the plurality of light emitting elements ; wherein: the base member has a plurality of recessed portions each opened on the rear surface and the bottom surface , the plurality of recessed portions including a first recessed portion; the substrate includes a third wiring portion covering an inner wall of the first recessed portion, and a via which runs through the base member from the front surface to the rear surface ; and the via electrically connects the first wiring portion , the second wiring portion and the third wiring portion to each other, wherein the via is in direct contact with the first wiring portion , the second wiring portion and the third wiring portion . a base member including a front surface extending in a first direction as a longer direction and a second direction as a shorter direction, a rear sur-face located opposite to the front surface , a bottom surface adjacent to and perpendicular to the front surface , and a top surface located opposite to the bottom surface , and a first wiring portion located on the front surface , and a second wiring portion located on the rear surface ; a plurality of light emitting elements including a first light emitting element electrically connected with the first wiring portion and placed on the first wiring portion ; a first reflective member covering lateral surfaces of the plurality of light emitting elements and the front surface of the base member ; and a light-transmissive member disposed over the plurality of light emitting elements ; wherein: the base member has a plurality of recessed portions each opened on the rear surface and the bottom surface , the plurality of recessed portions including a first recessed portion; the substrate includes a third wiring portion covering an inner wall of the first recessed portion, and a via which runs through the base member from the front surface to the rear surface ; and the via electrically connects the first wiring portion , the second wiring portion and the third wiring portion to each other, wherein the via is in direct contact with the first wiring portion , the second wiring portion and the third wiring portion . the base member has a plurality of recessed portions each opened on the rear surface and the bottom surface , the plurality of recessed portions including a first recessed portion; the substrate includes a third wiring portion covering an inner wall of the first recessed portion, and a via which runs through the base member from the front surface to the rear surface ; and the via electrically connects the first wiring portion , the second wiring portion and the third wiring portion to each other, wherein the via is in direct contact with the first wiring portion , the second wiring portion and the third wiring portion . <EOS>