It is an object to provide a repairing method for a wall member with flow passages capable of reducing the time and the cost required for a partial repairing work on the wall member with flow passages. The repairing method for the wall member with flow passages includes a removal stage of removing a portion of the wall member with flow passages (1) provided with plural flow passages (4) between the base member (2) and the plate member (3), the base member welding stage of welding the repairing base member (6) to the portion removed in the removal stage, a flow passage forming stage of providing plural overlay welds on the repairing base member (6) and forming the flow passages (4) between the overlay welded beads (8), and a plate member welding stage of welding a repairing plate member (9) onto surfaces of the plural overlay welded beads (8).