There is provided an aligning implement for optical fibers by which an optical fiber array having a plurality of optical fibers aligned substantially in parallel with one another with a predetermined pitch therebetween can easily be fabricated. The aligning implement comprises a substrate having a plurality of ridges formed on one surface thereof with the predetermined pitch and aligned substantially in parallel with one another, and a cover member having a plurality of ridges formed on one surface thereof with the predetermined pitch and aligned substantially in parallel with one another. The widths of the ridges of the substrate and of the cover member are set to have such values that the cover member is movable relative to the substrate in the direction substantially orthogonal to the ridges in a state that the ridges of the substrate and of the cover member are engaged with one another, and each optical fiber is nipped, positioned and held between the wall surface of each ridge of the substrate and the wall surface of each corresponding ridge of the cover member by sliding of the cover member in the direction substantially orthogonal to the ridges.