The method of manufacturing a compound thin-film photovoltaic cell includes preparing a metal substrate, whose main constituent is iron, containing aluminium (Al) and chromium (Cr), and forming an insulating layer on an element forming surface of the metal substrate by baking an insulating material; depositing first electrode layer on the insulating layer; depositing a compound light absorption layer on the first electrode layer; and depositing a second electrode layer on the compound light absorption layer, wherein in the forming the insulating layer, an alumina layer is formed at least on a back surface of the metal substrate by thermal oxidation while baking the insulating material.