We studied the electronic structure of Ca-10(Pt4As8)(Fe2-xPtxAs2)(5) for two platinum concentrations with different T-c using ARPES. From the carrier number estimated from the areas of FS sheets, we found that the Pt substitution induces electron doping into the Fe2As2 layers (effectively two electrons per Pt atom). In addition, we found that the FS nesting condition in x = 0.25 is stronger than that in x = 0.42, indicating close correlation between the FS nesting and T-c.