PROBLEM TO BE SOLVED: To provide a sleep disorder-improving agent for improving sleep disorder well, and a food having a new function based on glycine.SOLUTION: A composition or the sleep disorder-improving agent includes glycine as an effective component and improves the sleep disorder. The sleep disorder-improving agent contains glycine as the effective component and is used for adding to foods, drinks, dietary supplements, foods with health claims, and supplements.COPYRIGHT: (C)2011,JPO&INPIT【課題】従来にない熟眠障害改善剤の提供。【解決手段】グリシンを有効成分として含有する熟眠障害改善のための組成物、又は熟眠障害改善剤。【選択図】なし