A method of manufacturing a flexible printed circuit board that includes a component mounting section having lands, a plurality of flexible cable sections having wirings and extending in different directions from the component mounting section, and a connection section having terminals connected with the land through the wiring, the method including manufacturing partial FPCs in a sheet in a unit of a partial FPC that includes a partial component mounting section that is a part of the component mounting section, a cable section extending from the partial component mounting section, and a connection section disposed in the cable section, cutting out the partial FPC from the sheet, performing an alignment using alignment targets of the partial FPC and a support plate so that the partial component mounting sections of respective partial FPCs configure the component mounting section, and fixing the partial FPCs onto the support plate.