A light emitting device includes: a substrate; a first metal film formed on the substrate; quadrilateral light emitting elements arranged in a line at an interval d1, with second metal films on lower faces, and a die bond fixes the first and second metal films together. A diagonal of the respective quadrilateral outlines of the light emitting elements is aligned with the line. One of a distance DL from a light emitting element on one end among the light emitting elements arranged in the line to an end of the substrate, and a distance DR from a light emitting element on the other end among the light emitting elements arranged in the line to an end of the substrate is equal to or shorter than the interval d1.