A heat-shrinkable resin film which has a heat shrinkage in the maximum shrinkage direction of 20% or higher when a 10 cm by 10 cm square sample cut out thereof is immersed in 85°C water for 10 seconds, pulled out, subsequently immersed in 25°C water for 10 seconds, and then pulled out, characterized in that the content of nitrogen atoms in a film surface is 0.1 to 3.0% and the film surface has a wet tension of 36 mN/m or higher; and a film roll obtained by winding up the heat-shrinkable resin film, characterized in that when the rolled film is sampled at a first sampling part located up to 2 m apart from the end of the rolled film and at other sampling parts located after the first sampling part at intervals of about 100 m and the average nitrogen content of each sample is calculated, then the nitrogen content of each sample is within the ±0.8% range based on that average nitrogen content.