To enable the high-speed cold rolling of both ferrite and austenite stainless steel with the same rolling oil and obtain steel plate of high gloss by specifying the kinds of ionic emulsifiers and the pH of the liquid emulsion.

When stainless steel is cold-rolled by using an emulsion oil containing ionic emulsifier(s) as a rolling oil, the pH of the emulsion oil is made weakly acidic, 4.0-6.5 pH in the case that a cationic emulsifier is used, while the pH is adjusted to 7.5-9.5, weakly alkaline, in the case that an anionic emulsifier is employed. Further, in the emulsion tank, the emulsion is separated into high-concentration and large particle size emulsion and low-concentration fine particle size emulsion to collect individual emulsions. These fractions are properly selected, mixed and used as a rolling oil.