Heat-shrinkable polyester film and packaging

A heat-shrinkable polyester film, satisfying below requirements (1) to (4), wherein a main shrinkage direction is a longer direction, and the requirements are as follows:

• (1) a hot water shrinkage ratio of the film when being immersed in hot water at 98° C. for 10 seconds in the film main shrinkage direction is 40% or more;
• (2) difference between a hot water shrinkage ratio of the film in the main shrinkage direction when being immersed in hot water at 70° C. for 10 seconds and the hot water shrinkage ratio at 98° C. in the main shrinkage direction is 0% or more and 20% or less;
• (3) a main component is ethyleneterephthalate, and an amount of a diethyleneglycol (DEG) component is 10 mol % or more and 25 mol % or less with respect to 100 mol % of a polyhydric alcohol component in all of polyester resin that composes the film;
• and
• (4) difference between a hot water shrinkage ratio of the film in the main shrinkage direction, after the film is left under an atmosphere at a temperature of 40° C. and relative humidity of 85% for 28 days and is subsequently immersed in hot water at 70° C. for 10 seconds, and the hot water shrinkage ratio of the film before such time passage is 0% or more and 5%% or less.