A pipe lining method is provided for accurately cutting or punching out a pipe liner bag (4) after being lined on an inner wall of a pipe (10) with a good operability while preventing the operational environment from being contaminated. A fluid pressure is applied to act on a pipe liner bag (4) introduced in a pipe (10) to press the pipe liner bag onto the inner wall of the pipe. A thickness reducing member (3) is brought into contact with the outer surface of the pipe liner bag (4) to partially reduce the thickness of the pipe liner bag. A predetermined pipe lining operation is performed with the above state maintained. Then, an external force is applied to a thickness reduced portion (4a) of the pipe liner bag (4) to break the portion. <IMAGE>
