A nobel therapeutic agent for diabetes which can suppress occurrence of side effects such as persistent hypoglycemia is provided. The active ingredient is a derivative of 1,1-diphenylsemicarbazide or 1,1-diphenylthiosemicarbazide. In particular, the active ingredient is a derivative of 1,1-diphenyl-4-cyclohexyl-semicarbazide or 1,1-diphenyl-4-cyclohexyl-thiosemicarbazide exhibiting hypoglycemic action when orally administered.