PURPOSE: To manufacture superior tunnel liner by a method wherein the deformation of a form is prevented from developing by deforming a drum shell due to unbalance, which develops when centrifugal molding is performed under the conditions that partition plates are mounted directly on the form drum shell.

CONSTITUTION: Discrete forms 1a, 1b, 1c and 1d of a tunnel liner are independently produced. By providing a ribe 13 at the back of an arcuate bottom plate 11 of each discrete form, rigidity is given to the bottom plate. The discrete forms are fixed onto the inner surface of a centrifugally molding drum shell 2.