[Solving means] A thienotriazolodiazepine compound of the following formula (I) a pharmaceutical agent containing the compound as an active ingredient, and a production intermediate and a production method of the thienotriazolodiazepine compound. [Effect] Since this compound has an inhibitory action on costimulatory signal from CD28 on T cell, it is useful for the prophylaxis or suppression of rejection reaction in transplantation of organ or bone marrow and the like, and the prophylaxis or treatment of autoimmune diseases or allergic diseases.
