To prevent a sheet member such as aluminum foil form being shifted relative to the axial direction of a core such as a paper tube by forming partially recess parts and projection parts on the outside surface relative to the axial direction of a cylindrical core around which a sheet member is wound.

The paper tube is formed by winding spirally a third belt-like paper 209 different from the third belt-like paper of other paper tube. However, the third belt-like paper 209 is wound spirally at predetermined distances allowing for interstices (for example, a width of 5mm), and the distances form recess parts 203. The recess parts 203 is configured to be depressed for a first step 203a and a second step 203b. Also, a paper tube is available, in which paper having a narrow width of the same as interstices is wound with so many folds as a third layer for forming projection parts and recess parts. Furthermore, a paper is also available, in which a piece of a belt is wound in a ring shape on a cylinder formed by winding belt-like paper spirally.