To provide a method which enables a lining material to be pulled out in a deterioration in the lining material making an inner surface of an existing pipeline lined to be repaired, reinforced and regenerated.

A slit 4 is formed in the lining material 2 with which a main 1 is lined; and a height-strength linear element 5 locked near the slit 4 is pulled so that the lining material 2 can be pulled out while being separated from the main 1. The inside of the lining material 2, with which the main 1 is lined, is airtightly sealed, and decompressed for the separation of the lining material from the main 1 and a reduction in a cross-sectional shape; and after that, the lining material 2 is pulled out from the main 1. Additionally, twisting is applied from one end of the lining material 2 with which the main 1 is lined, so that the lining material 2 can be separated from the main 1; and sequentially, the lining material 2 is pulled out from the main 1.