To improve reliability by preventing separation of a sheet material attached on a flexible printed circuit, provided is a flexible printed circuit including a printed board body and a reinforcing board. A leaked portion of an adhesive agent is formed to leak in an outward direction relative to an end surface of the reinforcing board. The leaked portion adheres to part of the end surface of the reinforcing board to be continuous from a lower end of the end surface to form an inclined surface tapered in the outward direction. The leaked portion is formed such that a portion thereof that covers the end surface has an adhesion height hA, as measured from an adhesive surface of the reinforcing board, of greater than 0% and not greater than 80% of the thickness H1 of the reinforcing board.