According to one aspect of the present invention, a buckle for a clothing belt includes a first rotating body supported by the first shaft so as to be rotatable, an open end portion of the first rotating body being capable of being disposed between a bar and a back plate of a base body by making a first shaft slid; and a second rotating body supported by a second shaft so as to be rotatable with the second shaft as a fulcrum, formed so as to have a second convex portion, and capable of hindering a movement of the first rotating body in a direction opposite to the bar side with the second convex portion in a state where the second convex portion is rotated so as to be pushed in toward the opening portion of the back plate.