The present invention relates to austenitic steel, which can realize high-temperature properties equal to or greater than conventional heat-resistant stainless steel, while replacing nickel (Ni), which is an expensive alloy element rich in a heat resistant stainless steel used at a very high temperature such as for a turbocharger, with a low-cost alloy element. The austenitic steel according to the present invention comprises 0.4 to 0.5 wt% of C, 1.0 to 2.0 wt% of Si, 5.0 to 8.0 wt% of Mn, 13.5 to 16.5 wt% of Ni, 23 to 26 wt% of Cr, the remainder being Fe and other unavoidable impurities, wherein the ratio CMn/CNi of the Mn content to the Ni content in the alloy element is maintained in the range of 0.3 to 0.9.