To provide a substrate which is used for an adhesive tape, generates no poisonous gas such as chlorine gas, is scarcely tacky, and has the same flexibility as that of polyvinyl chloride tape.

This substrate for the adhesive tape comprises at least one of layers each comprising a copolymer which is obtained by copolymerizing (a) an α-olefin with (b) a cyclic olefin and/or (c) an aromatic vinyl compound and has a glass transition temperature of -30 to 40°C, an elastic recovery of ≥20%, a 25°C storage elastic modulus E' of ≤500 MPa, and a 25°C tan δof ≥0.2.