To provide a plate cylinder driver of a coating apparatus for a printer for shortening a preparing time such as a plate replacing operation or the like.

A driving force is transmitted from a sheet printer body to an impression cylinder gear 2. The gear 2 is engaged with an intermediate drive gear 3, which is mounted coaxially with an intermediate driven gear 4. The gear 4 is engaged with an intermediate coupling gear 5. The gear 5 is engaged with a plate cylinder gear 6. A clutch 7 interrupts or transmits a driving force from the gear 3 to the gear 4 by an external operation. A driving force of a driving motor 9 is output to the gear 5. A clutch 8 interrupts or transmits a driving force from the motor 9 to the gear 5 by an external operation.