There are provided a wear resistant austenitic steel having superior machinability and toughness in weld heat affected zones and a method for producing the austenitic steel. The austenitic steel includes, by weight %, manganese (Mn): 15% to 25%, carbon (C): 0.8% to 1.8%, copper (Cu) satisfying 0.7C-0.56(%)≦Cu≦5%, and the balance of iron (Fe) and inevitable impurities, wherein the weld heat affected zones have a Charpy impact value of 100 J or greater at −40° C. The toughness of the austenitic steel is not decreased in weld heat affected zones because the formation of carbides during welding is suppressed, and the machinability of the austenitic steel is improved so that a cutting process may be easily performed on the austenitic steel. The corrosion resistance of the austenitic steel is improved so that the austenitic steel may be used for an extended period of time in corrosive environments.