To provide a cognitive function improver useful for improving cognitive functions such as storage, learning ability.SOLUTION: A cognitive function improver contains a pressed or extracted material of mannitol/Agaricus bisporus as an active ingredient.SELECTED DRAWING: None【課題】記憶、学習能力等の認知機能の改善に有効な認知機能改善剤の提供。【解決手段】マンニトール/ツクリタケの圧搾物又は抽出物を有効成分とする認知機能改善剤。【選択図】なし