Abstract: Provided is a roll body capable of effectively suppressing the occurrence of a telescope phenomenon even if the ambient temperature during transportation and storage of the roll body becomes higher than that during production of the roll body. A roll body RB according to the present invention configured by winding a belt-shaped web around a winding core that thermally expands or contracts due to an influence of a surrounding environment is characterized in that a linear expansion coefficient of the web in a thickness direction is in a range of 60 to 150 times a linear expansion coefficient of the web in a longitudinal direction, and the winding core has a linear expansion coefficient in a range of 20×10?6/K to 100×10?6/K and a Young's modulus in a range of 0.2 GPa to 0.5 GPa.