An organic thin film photovoltaic device (1) includes: a substrate (10); a first electrode layer (11) disposed on the substrate; a hole transport layer (12) disposed on the first electrode layer; a bulk heterojunction organic active layer (14) disposed on the hole transport layer; a second electrode layer (16) disposed on the bulk heterojunction organic active layer; a sealing glass (40) configured to be opposed to the substrate 10, and configured to seal a laminated structure composed of the first electrode layer, the hole transport layer, the bulk heterojunction organic active layer, and the second electrode layer; and a glass frit (36) disposed between the sealing glass and the substrate and configured to seal the laminated structure. There is provided: an inexpensive organic thin film photovoltaic device of which durability is improved, allowing further weight saving and thin-layering; and a fabrication method of such an organic thin film photovoltaic device.