[Problem] To provide a prophylactic/therapeutic agent against, for example, nerve diseases and the like such as ischemic brain disease and neurodegenerative disease, or a prophylactic/therapeutic agent against diseases against which antioxidant action is effective, as a cell protecting agent, in particular as an inhibitor of brain cell damage or brain cell death.[Means of Solving the Problem]A compound represented by Formula (1), or a pharmaceutically acceptable salt, solvate, hydrate, or prodrug thereof: