the base drum 2 is vertically conveyed it is dried the drier 24 includes a suction slit member 15 having a suction slit 17 suction chamber 16 and suction nozzle 20 and cylinder members 14 for rectifying the flow which are concentrically attached to the upper and lower portions of the suction slit member 15 the sucking operation is conducted by a plurality of suction nozzles 20 and then the sucked air flow is made uniform with respect to the circumferential direction by the action of the suction chamber 16 and the suction slit 17 which are constructed to be uniform with respect to the circumferential direction in this case a turbulence of air is caused in a space formed between the inner surface of the suction slit member 15 and the outer circumferential surface of the coated base drum 2 and a turbulence of air is also caused in a space formed between the inner surfaces of the upper and lower cylindrical members 14 and the outer circumferential surface of the coated base drum 2 the turbulence is a little suppressed by a buffer space 19 and a uniform air flow 18 is made for drying the base drum as described above the coating film is dried until it does not flow down by its own weight with reference to fig1 a to fig1 e which are views for showing the process conditions the first method of the first embodiment of the invention will be described in which the continuous base drum on which the coating film has been coated and set in the above.