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 surface 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 light emitting element electrically connected with the first wiring portion and placed on the first wiring portion ; and a first reflective member covering a lateral surface of the light emitting element and the front surface of the base member ; wherein: the base member has a recessed portion opened on the rear surface and the bottom surface ; the substrate includes a third wiring portion covering an inner wall of the 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 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 surface 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 light emitting element electrically connected with the first wiring portion and placed on the first wiring portion ; and a first reflective member covering a lateral surface of the light emitting element and the front surface of the base member ; 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 surface 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 light emitting element electrically connected with the first wiring portion and placed on the first wiring portion ; and a first reflective member covering a lateral surface of the light emitting element and the front surface of the base member ; wherein: the base member has a recessed portion opened on the rear surface and the bottom surface ; the substrate includes a third wiring portion covering an inner wall of the 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, the base member has a recessed portion opened on the rear surface and the bottom surface ; the substrate includes a third wiring portion covering an inner wall of the 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>