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.