PROBLEM TO BE SOLVED: To find out a novel JAK3 inhibitor, and to provide a compound with a novel chemical structure having JAK3 inhibiting activity.SOLUTION: The JAK3 inhibitor contains at least one compound represented by general formula (1) and salts thereof as an active ingredient.【課題】新規JAK3阻害剤を見出すこと、およびJAK3阻害活性を有する新規化学構造の化合物を見出すこと。【解決手段】下記一般式(1)で表される化合物又はその塩の少なくとも一つを有効成分として含有するJAK3阻害剤。【選択図】なし