A base film for dicing sheets that is used in a dicing sheet comprising the base film and a pressure sensitive adhesive layer laminated on one surface of the base film. The base film comprises at least a first resin layer that is in contact with the pressure sensitive adhesive layer of the dicing sheet and a second resin layer that comes into contact with the first resin layer when the base film for dicing sheets is wound up. The second resin layer has a crystallinity of 28% to 45%, The ratio of a tensile elastic modulus of the first resin layer to a tensile elastic modulus of the second resin layer is 1.2 to 3.0. The ratio of a thickness of the first resin layer to a thickness of the base film for dicing sheets is 25% to 80%.