Provided is a carrier for a flexible substrate which is capable of handling a flexible substrate during a flexible substrate processing process, while allowing the flexible substrate to be easily separated. Also provided is a substrate processing apparatus, including the carrier, and a method of manufacturing a flexible display apparatus. The carrier includes a substrate supporting portion having a top surface including a mounting surface, an outer circumferential surface, surrounding the mounting surface, and a first heat cutting portion. The first heat cutting portion is located outside the mounting surface so as to be exposed on the top surface and generates heat when a current flows through the first heat cutting portion.