FUSION SPLICER

A fusion splicer includes: a heater that heats a glass of an optical fiber; a pair of clamps that clamp a coated part of the optical fiber, wherein the pair of clamps is constituted by: a lower clamp on which a coated part of the optical fiber is disposed; and a coated part clamp that presses the coated part of the optical fiber against the lower clamp; a windproof cover that covers the heater and the coated part clamp; a retreat mechanism that causes the coated part clamp to retreat from the lower clamp; an opening/closing mechanism that opens and closes the windproof cover; and a pair of glass clamps attached to an inner surface of the windproof cover.