A light-emitting device comprising: a substrate comprising: a base member including: a front surface extending in a first direction and a second direction the first direction being a longitudinal direction and the second direction being a width direction of the base member; a back surface opposite to the front surface; and a bottom surface and an upper surface adjacent and perpendicular to the front surface while being opposed to each other; a first wiring disposed on the front surface; a second wiring disposed on the back surface; and a via hole electrically connecting the first wiring and the second wiring; at least one light-emitting element electrically connected to and disposed on the first wiring; and a covering member having light reflectivity and covering a lateral surface of the light-emitting element and a front surface of the substrate, wherein the base member defines a plurality of depressed portions separated from the via hole in a front view and opening on the back surface and the bottom surface, and wherein the substrate includes a third wiring covering at least one of inner walls of the plurality of depressed portions and electrically connected to the second wiring, wherein a depth of each of the plurality of depressed portions along a third direction that is defined from the back surface toward the front surface is larger on a bottom surface side of the base member than on an upper surface side of the base member, and characterised in that, in a sectional view parallel to the second direction and the third direction, each of the depressed portions includes a parallel portion extending from the back surface in the third direction and an inclined portion inclined from the bottom surface toward the direction in which the thickness in the third direction of the base member increases, such that the depth of the depressed portion in the third direction is greater on the bottom surface side of the base member than on the upper surface side of the base member. a substrate comprising: a base member including: a front surface extending in a first direction and a second direction the first direction being a longitudinal direction and the second direction being a width direction of the base member; a back surface opposite to the front surface; and a bottom surface and an upper surface adjacent and perpendicular to the front surface while being opposed to each other; a first wiring disposed on the front surface; a second wiring disposed on the back surface; and a via hole electrically connecting the first wiring and the second wiring; a base member including: a front surface extending in a first direction and a second direction the first direction being a longitudinal direction and the second direction being a width direction of the base member; a back surface opposite to the front surface; and a bottom surface and an upper surface adjacent and perpendicular to the front surface while being opposed to each other; a front surface extending in a first direction and a second direction the first direction being a longitudinal direction and the second direction being a width direction of the base member; a back surface opposite to the front surface; and a bottom surface and an upper surface adjacent and perpendicular to the front surface while being opposed to each other; a first wiring disposed on the front surface; a second wiring disposed on the back surface; and a via hole electrically connecting the first wiring and the second wiring; at least one light-emitting element electrically connected to and disposed on the first wiring; and a covering member having light reflectivity and covering a lateral surface of the light-emitting element and a front surface of the substrate, wherein the base member defines a plurality of depressed portions separated from the via hole in a front view and opening on the back surface and the bottom surface, and wherein the substrate includes a third wiring covering at least one of inner walls of the plurality of depressed portions and electrically connected to the second wiring, wherein a depth of each of the plurality of depressed portions along a third direction that is defined from the back surface toward the front surface is larger on a bottom surface side of the base member than on an upper surface side of the base member, and characterised in that, in a sectional view parallel to the second direction and the third direction, each of the depressed portions includes a parallel portion extending from the back surface in the third direction and an inclined portion inclined from the bottom surface toward the direction in which the thickness in the third direction of the base member increases, such that the depth of the depressed portion in the third direction is greater on the bottom surface side of the base member than on the upper surface side of the base member.