The solidification microstructure of spheroidal graphite cast iron was analyzed by electron probe micro analysis (EPMA) and scanning transmission electron microscopy (STEM), focusing on the distribution of Cu. EPMA and STEM results clarified the following tendency in the distribution of Cu in spheroidal graphite cast iron containing Cu within the pearlite matrix : (1) Cu-Sn-Mg-enriched regions were distributed in the pearlite matrix, and (2) the distribution of metallic elements of Cu, Sn, and Mg in Cu-Sn-Mg enriched regions was not homogeneous, and a composite of metallic and oxide phases was formed. EPMA with a field-emission electron gun (FE-EPMA) and FE-STEM apparatus with a silicon drift detector were highly effective for clarifying the distribution of Cu, compared with conventional EPMA employing a thermionic-emission electron gun (TE). The high-resolution observation using FE-STEM, and the combination with TE-EPMA, FE-EPMA and FE-STEM, are powerful tools for clarifying the distribution of the Cu element in spheroidal graphite cast iron.