A method of manufacturing a substrate joint body by mounting a TFT on a wiring substrate includes a step of arranging an electrode pad of the wiring substrate and an electrode pad of the TFT at a predetermined interval and mechanically coupling the wiring substrate and the TFT with a adhesive and a step of electrically coupling the wiring substrate and the TFT by growing a bump from the electrode pad of the wiring substrate and/or the electrode pad of the TFT.