PURPOSE: To form continuously a high-quality interposing plate with a dimensionally stable resin rib at high speed by preparing a resin feeder providing molten resin into molding grooves of a transfer roller, a base paper feeder providing the transfer base paper onto the outer surface of the transfer roller and a release agent coating device coating the molding groove portion with a film of release agent.

CONSTITUTION: An interposing plate manufacturing device consists of a transfer roller 2 having a number of annular molding grooves 1 in its periphery, a resin feeder 4 feeding molten resin into the molding grooves 1 by means of a gun nozzle 3, a base paper feeder 5 feeding a transfer base paper W onto the outer surface of the transfer roller 2 at a specified speed and a release agent coating device 6 forming a coating film of release agent before resin feeding. The release agent coating device 6 is arranged forward from the position of the gun nozzle 3 in the direction of revolution of the transfer roller, and composed of a spray gun 18 prepared toward the molding grooves 1 of the transfer roller 2, a controller 19 controlling the feeding of release agent and a feeder part 20 reserving and feeding the release agent, and coats at least the molding grooves 1 of the transfer roller 2 with the film of release agent before resin feeding.