Fe—Cr—Ni—Mo alloy having superior surface properties and a method for producing the same using a commonly used apparatus at low cost. The Fe—Cr—Ni—Mo alloy has (% indicates mass %): C: ≤0.03%, Si: 0.15 to 0.5%, Mn: 0.1 to 1%, P: ≤0.03%, S: ≤0.002%, Ni: 20 to 32%, Cr: 20 to 26%, Mo: 0.5 to 2.5%, Al: 0.1 to 0.5%, Ti: 0.1 to 0.5%, Mg: 0.0002 to 0.01%, Ca: 0.0002 to 0.01%, N: ≤0.02%, O: 0.0001 to 0.01%, freely contained components of Co: 0.05 to 2% and Cu: 0.01 to 0.5%, Fe as a remainder, and inevitable impurities, wherein MgO, MgO.Al2O3 spinel type, and CaO—Al2O3—MgO type are contained as oxide type non-metallic inclusions, ratio of number of MgO.Al2O3 spinel type to all oxide type non-metallic inclusions is ≤50%, and CaO—Al2O3—MgO type contains CaO: 30 to 70%, Al2O3: 5 to 60%, MgO: 1 to 30%, SiO2: ≤8%, and TiO2: ≤10%.