To provide a method of manufacturing a display device, by which the number of manufacturing steps is reduced, defective mounting of a device and substrate crackings except in a predetermined region occurring during splitting a strip-shaped substrate are excellently suppressed.

The method of manufacturing the display device includes: a first step of preparing the strip-shaped substrate where a plurality of unit display regions are provided in parallel; a second step of forming deficient parts between adjacent unit display regions on the strip-shaped substrate respectively; a third step of temporarily connecting predetermined mounting devices to side ends of the plurality of unit display regions, respectively; and a fourth step of mainly connecting the mounting devices and also parting the strip-shaped substrate into the plurality of unit regions by applying pressing force to a temporary connection region and a deficient formation region of at least a predetermined mounting device.