To produce a large size ring high in dimentional precision by applying heat treatment to a ring in which a groove is to be formed on inner/outer diameter faces in the peripheral direction by cold rolling a steel tube extruded by a medium press machine as a base material, and then sizing, shot-peening and pickling the ring.

An austenitic stainless steel, e.g. SUS304 extruded by a medium press machine of 2000t is cut to a ring by a band saw, etc. This ring is subjected to cold rolling at an expanding rate of 1.2-1.8. After heating to about 1070°C, the ring is subjected to rapid cooling solid solution heat treatment, after a roundness/external dimension is made by sizing, shot blasting is conducted to remove a scale generated by heat treatment. By this method, without using a large press machine and a cold drawing machine difficult to contact a small quantity and many kind production in high cost, a large diameter ring having an outer diameter of ≥145 mm is obtained in high precision.