A method for lining a branch pipe (3) comprising the steps of: preparing a tubular liner bag (4) by sewing a rectangular nonwoven resin-absorbent fabric (5) into a tubular shape with one end closed; attaching an impermeable plastic film over the external surface of this tubular liner bag; soaking the nonwoven resin-absorbent fabric with a hardenable fluid resin; everting the liner bag into the branch pipe until the eversion head (4b) of the liner bag is stopped by the inner wall of the main pipe; forcing the eversion head of the liner bag to turn downstream in the main pipe, thus allowing the liner bag to evert entirely; hardening the hardenable fluid resin while inflating the liner bag; and removing that portion of the liner bag which protrudes into the main pipe. <IMAGE>
