The method of manufacturing a mold for steel, mold steel material, the method of manufacturing the mold pre-hardened material, and the mold for pre-hardened material

In the present invention, there is provided a molten steel having been vacuum refining, C: 0.005 to 0.1 mass%, Ni: 1.0 to 5.0 wt%, Cr: 3.0 to 8.0 mass% , Mo: 0 ultra 2.0 wt% or less, Cu: 0 ultra 3.5 wt% or less, and Al: 0 include ultra 2.0 mass% or less, the amount of O is not more than 0.005 wt%, a first step of the amount of N to prepare the molten steel a having a chemical composition is not more than 0.03 wt%, respectively to reduce the amount of amount and N in O of by refining in solution steels a to the molten steel a a second step, third step and method for producing a mold steel material having a casting said molten steel B is provided to obtain a molten steel B Te.