PURPOSE: To facilitate the control of registration in stages for coating of recording media and sticking of a substrate and back material by forming rugged parts perpendicularly to the longitudinal direction on the parts of an extruded sheet where the recording media are not provided to impart bendability to the extruded sheet at the time of forming the extrusion molded substrates.

CONSTITUTION: The rugged parts 7, 6 are deliberately provided between a sheet of the stamper provided on the outer peripheral surface of a groove roller 2 and the stamper adjacent thereto. Further, the extruded sheet 4 is molded on two sets of rollers 1, 3 disposed above and below to face the grooved roller 2 in such a manner as to fit to the rugged parts 7, 6 of the grooved roller 2 and no to generate the volume strain of the extruded sheet 4. Stretchability and flexibility, are, therefore, imparted even to the thick substrate 8 while the continuity thereof is maintained. The easy control of the registration is executed in this way in the stages for coating of the recording media and sticking of the back material.