1. A heat shrinkable polyester film comprising a first polyester layer having voids (layer A) and a polyester layer (layer B) having a smaller porosity than layer A, which is formed at least on one surface of layer A, wherein the film has a brightness of not less than 70, which permits adhesion with a solvent, and wherein the film has a percentage of heat shrinkage in hot air at 95° C. of 30-90% in either direction of the heat shrinkable polyester film.