PURPOSE: To line the inner surface of an existing pipe held to a flowing water or stagnated water state with a hard tube by adapting a heating pressure expanding construction method without requiring pretreatment such as cut-off treatment.

CONSTITUTION: A process closing both end ports of an existing pipe 1 using closed type terminal pipes 3 having tube access ports 6 to seal water within the pipe 1 and drawing out the wire material 2 preliminarily provided in the pipe to the outside through the tube access ports 6, a process pushing out the water 12 in the pipe to the outside by the air introduced into the pipe under pressure to discharge the same and holding the interior of the pipe to predetermined air pressure to prevent the pentration of ground water into the pipe, a process inserting a hard tube in the pipe using the wire material 2 through the access ports 6 of the terminal pipes and a process heating and pressurizing the hard tube inserted in the pipe according to a usual method after the ground water penetration preventing process to expand the tube are provided.