PURPOSE: To provide a stainless steel for a high purity gas excellent in corrosion resistance and to provide its manufacturing method.

CONSTITUTION: (1) This austenitic stainless steel for a high purity gas is the one in which the totral content of Ti and Al is regulated to <0.2wt.% and the surface previously subjected to smoothing treatment so as to regulate the maximum roughness into ≤1μm is applied with an oxidized film with 100 to 1000 thickness in which the Cr content in the outermost layer is regulated to ≥60atomic%. (2) The method is to manufacture the austenitic stainless steel for a high purity gas in which the same austenitic stainless steel is previously subjected to treatment so as to regulate the maximum roughness into ≤1μm and is thereafter subjected to heating treatment at 750 to 1100°C in an atmosphere of an inert gas having ≤10-5Pa oxygen partial pressure or in a vacuum atmosphere. In this way, the stainless steel for a high purity gas in which moisture is hard to adsorb on the surface of the steel and also the subsequent desorption is easily executed even in the case it is adsorbed and also excellent in corrosion resistance to a corrosive gas can be obtd.