A shopping bag is provided that can be transformed for use as a file holder for storing documents and items such as a large envelope. The shopping bag includes a rectangle-shaped body part formed by a pair of front and back sheets, handles provided to the open side of the body, and a file part that is integrally formed with the body and that is turned into a rectangle-shaped file holder when separated from the body. The file part includes a separation line to be used for separating the file part from the body, a joint line formed inside of the separation line along the two sides of the separation line, at which the front and back sheets are joined together, and a cut-out part formed as a part of the separation line to be used as a starting point for separating the file part from the body.