To provide a steel for plastic molds which has both high machinability and high texturability.

The steel comprises, by mass%, over 0.25 to 0.40% C, 0.05 to less than 0.50% Si, over 0.9 to 1.5% Mn, up to 0.01% P, 0.02 to less than 0.08% S, 0.05 to 0.30% Ni, 0.30 to less than 1.35% Cr, 0.02 to less than 0.50% Mo, 0.02 to 0.30% V, 0.02 to 0.10% Zr, and less than 0.035% Al, with the balance being Fe and impurities, and is characterized in that K is up to 0.63, Ceq is 0.72 to 0.85, (wherein K and Ceq are represented by the following formulae), and concerning sulfide inclusions larger than 50 μm2 in size, the inclusions with an aspect ratio of at most 3.8 exist 2.5 pieces per mm2, and the inclusions with an aspect ratio of at least 7.0 exist 4.0 pieces per mm2. K=0.01(C%)+0.60(Si%)+0.12(Mn%)+3.5(P%)+4.10(S%)-0.19(Mo%)+0.10(Cr%)-0.10(Ni%). Ceq=(C%)+(Si%)/10+((Mn%)-32/55×(S%))/5+(Ni%)/23+(Cr%)/9+(Mo%)/2+(V%)/2.