A lens-attached light-emitting element for increasing an optical availability efficiency is provided. A lens-attached light-emitting element for structuring a light-emitting element array arranged in one dimension comprises a light-emitting element having an approximately U-shaped light-emitting area; and an approximately U-shaped composite lens including a combination of two cylindrical lenses arranged in a direction of the one dimension, one cylindrical lens, and four hemispherical lenses. Where the width in a direction of the one dimension of the light-emitting area is p, the thickness of the base portion of the composite lens is in the range of 0 0.71 p, a radius of curvature of each of the cylindrical lens and hemispherical lens is in the range of 0.20 p 0.47 p, and a center-to-center distance between at least two cylindrical lenses is in the range of 0.35 p 0.89 p.