To provide a
stainless steel material that has excellent overall
corrosion resistance and
pitting corrosion resistance in supercritical
corrosion environments, and excellent low-temperature
toughness in cryogenic environments. [Solution] The
stainless steel material according to this disclosure has the
chemical composition described in the specification, satisfies formula (1), has a yield strength of 758 MPa or less, and its
microstructure consists of retained
austenite of 5-30% by volume, ferrite of 0-5.0%, and the remainder being
martensite, and the elemental content, yield strength, and
volume fraction of the
microstructure satisfy formula (2). 0.10 ≤ Cu + W ≤ 2.20 (1) 0.01YS×(Ni+12Co) / (Vγ+3.3Vα′)≧0.0036 (2) In equations (1) and (2), the elemental symbols are substituted with the content of the corresponding element in units of
mass%, in equation (2), YS is substituted with the yield strength in units of MPa, Vγ is substituted with the
volume fraction of retained
austenite, and Vα′ is substituted with the
volume fraction of
martensite in units of %.