To provide a method for producing a forging whose steel kind is a 1%C-8%Cr series cold die steel and free from the generation of internal defects.

At the time of subjecting a cast ingot of a componental system composed of, by weight, 0.80 to 1.20% C, 0.20 to 2.0% Si, 0.30 to 2.00% Mn, 5.0 to 10.0% Cr, and the balance Fe with inevitable impurities to hot working, in the case the melting starting temp. of the segregated zone in eutectic carbide in the cast ingot is defined as Tm(°C), and the heating temp. in the case of the hot working of the cast ingot is defined as Tf(°C), the hot working is executed in the temp. range satisfying the following inequality of -130°C≤Tf-Tm≤0°C.