Abstract: A cone formed from paper such as used in speaker as a diaphragm, wherein the wing portions, which may function to reinforce the cone, are selectively arranged and extending from any point in the periphery of the larger diameter circle to any point in the smaller diameter circle of the cone which has a frusto-conical shape and a coating layer is applied to the entire surface of the cone, and a method for making a cone using a sheet of paper, wherein the method comprises steps of cutting a sheet of paper into a desired pattern simultaneously with seaming at least a pair of folding portions composed of a centeral folding line and two lateral folding lines equi-angularly and symmetricaly displaced to each side of the center line, forming wing portions by folding said lines, honding the facing surfaces of the folded portions and, coating the entire surface of the entire surface of the cone with moisture-proof material.