the vulcanization is carried out by press vulcanization and secondary vulcanization or steam vulcanization with the present vulcanization system the vulcanization speed is higher and a considerably distinguished compression set can be obtained even if the secondary vulcanization is omitted furthermore the secondary vulcanized products have better effects on these properties than the conventional vulcanization system these effect are remarkable particularly when a metal salt of dithiocarbamic acid and thiuram disulfide are used together the present invention will be described in detail below referring to examples and comparative examples one hundred parts by weight of acrylic rubber containing an active halogen group and a carboxyl group which was a copolymer consisting of 49 by weight of ethyl acrylate 25 by weight of n butyl acrylate 24 by weight of 2 methoxyethyl acrylate 1 5 by weight of vinyl chloroacetate and 0 5 by weight of methacrylic acid one part by weight of stearic acid 55 parts by weight of fef carbon black 2 parts by weight of an antioxidant noguard 445 made by uniroyal co 0 5 parts by weight of trithiocyanuric acid and parts by weight given in the following table of at least one of a metal salt of dithiocarbamic acid.