A heat-shrinkable polyester film is obtained which is extremely satisfactory in openability along a perforation, has exceedingly high productivity, and is less apt to split in the lengthwise direction in processing, e.g., printing. Provided is a label which is formed from the heat-shrinkable film and is satisfactorily tearable. The label is one formed from a tubular material which comprises as a base a heat-shrinkable film thermally shrinking mainly in the film width direction and which has been cut according to an object to be packaged, both edges in the film width direction having been bonded to each other. The tubular material has been thermally shrunk to constitute the label, with which at least part of the periphery of the object to be packaged is covered. The label has an angle tear strength in the direction perpendicular to the main shrinkage direction (i.e., in the film length direction) of 100-310 N/mm and a tensile break strength in the direction perpendicular to the main shrinkage direction (i.e., in the film length direction) of 50-300 MPa.