To provide a manufacturing method of a filled skutterudite alloy which can be used in a thermoelectric conversion element as it is without requiring a pulverizing and sintering step of a metal, to provide the alloy suitable for the thermoelectric conversion element manufactured by the method, and to provide a power generation system with high efficiency.

The method for manufacturing the filled skutterudite alloy comprises melting a raw material for the alloy comprising a rare earth metal R (wherein R is at least one of La, Ce, Pr, Nd, Sm, Eu and Yb), and a transition metal T, (wherein T is at least one of Fe, Co, Ni, Os, Ru, Pd, Pt and Ag) and metallic antimony (Sb), and rapidly solidifying the molten metal with a strip cast method, and a thermoelectric conversion module is thereby manufactured.