PURPOSE: To manufacture a stainless steel excellent in oxidation resistance and strength at a high temp. at a low cost by reducing Cr content in a ferritic stainless steel and also compositely adding Si, Al, and Mo, W, etc.

CONSTITUTION: This steel contains, by wt.%, 0.3-3.0% Si, 0.02-2.0% Mn, 3.5-9.9% Cr, 1.0<Al≤5.0%, 0.5-4.0% in total of one or two kinds of MO and W, respectively≤0.03% C, P, S, and ≤0.02% N as impurities and the balance Fe, whose OR value expressed by the formula I is ≥8.5, which further contains 0.01-1.0% in total of one kind or more among Nb, V, Ti, Zr, Ta, and Hf as an additional components or one or two kinds of 0.001-0.1% rare earth metal and 0.0005-0.03% Ca, the total amount of C and N is ≤0.03% and has the components which satisfy the formula II and is a ferritic stainless steel excellent in oxidation detion resistance and strength at a high temp..