A light-emitting device comprising: a substrate; a plurality of light-emitting elements arranged on the substrate in a row; electrode pad pairs formed on the substrate in one-to-one correspondence to the light-emitting elements, each electrode pad pair including two electrode pads (141a, 142a,..., 156a, 241a, 242a,..., 256a) located on the substrate at opposite sides of a corresponding light-emitting element in an arrangement direction of the light-emitting elements, characterised by protective elements provided in one-to-one correspondence to groups each constituted by at least three consecutive sets of light-emitting elements and electrode pad pairs corresponding thereto, each protective element being located between any two adjacent electrode pads included in different electrode pad pairs; and a sealing member provided on the substrate to seal the light-emitting elements, the electrode pad pairs, and the protective elements, wherein in each group, a distance between two electrode pads included in an electrode pad pair corresponding to a light-emitting element located closest to the protective element is shorter than a distance between two electrode pads included in any other electrode pad pair, and a distance between two electrode pads included in each electrode pad pair varies between at least two electrode pad pairs other than the electrode pad pair corresponding to the light-emitting element located closest to the protective element. a substrate; a plurality of light-emitting elements arranged on the substrate in a row; electrode pad pairs formed on the substrate in one-to-one correspondence to the light-emitting elements, each electrode pad pair including two electrode pads (141a, 142a,..., 156a, 241a, 242a,..., 256a) located on the substrate at opposite sides of a corresponding light-emitting element in an arrangement direction of the light-emitting elements, characterised by protective elements provided in one-to-one correspondence to groups each constituted by at least three consecutive sets of light-emitting elements and electrode pad pairs corresponding thereto, each protective element being located between any two adjacent electrode pads included in different electrode pad pairs; and a sealing member provided on the substrate to seal the light-emitting elements, the electrode pad pairs, and the protective elements, wherein in each group, a distance between two electrode pads included in an electrode pad pair corresponding to a light-emitting element located closest to the protective element is shorter than a distance between two electrode pads included in any other electrode pad pair, and a distance between two electrode pads included in each electrode pad pair varies between at least two electrode pad pairs other than the electrode pad pair corresponding to the light-emitting element located closest to the protective element. a distance between two electrode pads included in an electrode pad pair corresponding to a light-emitting element located closest to the protective element is shorter than a distance between two electrode pads included in any other electrode pad pair, and a distance between two electrode pads included in each electrode pad pair varies between at least two electrode pad pairs other than the electrode pad pair corresponding to the light-emitting element located closest to the protective element.