A flexible chip on film includes a base insulating layer, a metal layer disposed on an upper surface of the base insulating layer and including a circuit pattern, an integrated circuit chip disposed on an upper surface of the metal layer and electrically connected to the metal layer, a solder resist layer disposed on the metal layer and insulated from the integrated circuit chip, and a reinforcing layer disposed on an upper surface of the solder resist layer. When the chip on film COF is bent, a neutral surface, in which a vector sum of a tensile force and a compressive force becomes substantially zero, is placed in the metal layer.