There is provided a soft magnetic alloy for a perpendicular magnetic recording medium having a low coercive force, high amorphous properties, high corrosion resistance, and a high hardness; and a sputtering target for producing a thin film of the alloy. The alloy comprises in at. %: 6 to 20% in total of one or two of Zr and Hf; 1 to 20% of B; and 0 to 7% in total of one or two or more of Ti, V, Nb, Ta, Cr, Mo, W, Ni, Al, Si, and P; and the balance Co and/or Fe and unavoidable impurities. The alloy further satisfies 6≦2×(Zr%+Hf%)−B%≦16 and 0≦Fe%/(Fe%+Co%)