PURPOSE: To prepare a film consisting of a polyethylene-based resin having a specific density and a specific crystalline melting peak, having low temperature sealing property and antiblocking property, free from occurrence of fish eye and having good appearance quality, mechanical suitability and shape-retaining property of packaged materials.

CONSTITUTION: This film consists of a polyethylene resin having 0.860-0.920g/cm3 density, exhibiting one crystal melting peak and having ≥20°C temperature range from melt peak temperature to a temperature at which melting of total crystals is finished when measured using a differential scanning calorimeter(DSC), and having 1.5-3.5 ratio of weight average molecular weight to number-average molecular weight. In this resin, the range of temperatures indicated when the resin is eluted in rations of 10wt.% to 100wt.% by a cross fraction method is ≤30°C. The resin is produced by using a polymerization catalyst having such chemical structure that the active point becomes single. Metallocene compound containing quadrivalent transition metal is used as the catalyst. This film comprises a sealant layer consisting of a polyethylene resin and a substrate layer consisting of a polyethylene-based resin having ≥0.920g/cm3 density. The reinforcing layer may be laminated. The film is processed into a packaging container.