PURPOSE: To stably form colored layers having a target color tone on the surfaces of a stainless steel member by immersing this stainless steel member into a colored aq. soln. contg. a sulfuric acid and chromic acid and impressing pulse voltages by specific potentials and waveforms thereto.

CONSTITUTION: The stainless steel S and a counter electrode 3 consisting of Pt, etc., are immersed into the aq. soln. 2 for coloration of 5 to 25°C contg. the sulfuric acid at a concn. of 400 to 520g/l and the CrO3 at 200 to 250g/l. The low potential E1 of 0.5 to 1.0V and the high potential E2 of 1.20 to 1.24V on the basis of a satd. calomel electrode 4 as a reference electrode 4 are applied on the stainless steel respectively in a range of 5 to 30 seconds of the impression time T1 of the low potential E1 and the impression time T2 of the high potential E2 by operating a potentiostat 5 and a function generator 6. In addition, the impulsive AC potentials starting from the high potential E2 of the potentials having the ratio 1 to 3 of T1 /T2 are once impressed thereon. The thicknesses of the colored films on the stainless steel S formed in such a manner are previously determined. The impulsive potential are impressed on the stainless steel by as much as the number of times obtd. by dividing the thicknesses of the colored films for attaining the target color tone by the previously determined thicknesses, by which the chemically colored films having excellent wear resistance free from unequal colors, etc., are formed.