For the purpose of providing a method of die cast product of spheroidal graphite cast iron and a die cast product of spheroidal graphite cast iron having the number of spherical graphites of 3000/mm2 or more in an as cast state, there is disclosed a method of die cast product of ultrafine spheroidal graphite cast iron, including the steps of: a melting step of heating and melting raw materials made of cast iron to obtain source melting metal; a spheroidizing treatment step in which a spheroidizing treatment is performed; an inoculation step of inoculating; and a casting step of casting in a die mold. The amount of nitrogen is adjusted so that the amount of nitrogen generated in the time of melting becomes 0.9 ppm (mass) or less.