Abstract: A folding box of the type having a front side provided with a removable window cover, and a backside provided with a central bending folding, includes a flap hingedly connected with the backside and bendable along a folding line which parallels the bending fold. The flap has opposing sides which extend transversely to the bending fold, with at least one side being provided with a locking member which cooperates with a complementary locking member of the backside.