The present invention relates to a food composition for cognitive function improvement, a cognitive function improving agent, and a production method thereof. The food composition for cognitive function improvement or the cognitive function improving agent contains L-ergothioneine as an active ingredient. The food composition for cognitive function improvement can be used in the improvement of memory, can be used to improve or prevent mild dementia, can be used to improve or prevent dementia, and can be used to improve attentiveness.本發明係有關於一種認知功能改善（cognitive function improvement）用食品組成物（food composition）、認知功能改善劑（cognitive function improving agent）、及其製造方法，其係含有麥角硫因（L-ergothioneine）作為有效成分的認知功能改善用食品組成物或認知功能改善劑。認知功能改善用食品組成物等可以用於記憶力（memory）的改善；認知功能改善用食品組成物等可以用於改善或預防輕度認知症；認知功能改善用食品組成物等可以用於改善或預防認知症；認知功能改善用食品組成物等可以用於改善注意力（attentiveness）。
