To provide a manufacturing method for high strength and spherical graphite cast iron for securing stably the strength/ elongation of a substance, not causing deterioration in strength and elongation even if the thickness is increased.

In manufacturing the spherical cast product formed with a part with 50 mm or more thickness, a spherical graphite cast molten metal with the constituent of C: 3.0-4.0%, Si: 1.5-2.5%, Mn: 0.1-0.5%, Mg: 0.01-0.07%, P: 0.03% or less, S: 0.010% or less, Cu: 0.1-0.7%, Ni: 1-2% is tapped into a sand mold disposed with a direct cooling metal of 30% or more of casting volume so as to make the cast.