An ultraviolet drying device (37) and a photoelectric sensor (70) for detecting the outer surface of a transport cylinder (36) are provided at a position close to the outer surface of the transport cylinder (36) arranged downstream in a sheet-like material convey direction of a reverse printing unit (11) for subsequent printing. When the ultraviolet drying device (37) is turned on and the photoelectric sensor (70) detects that a contamination-preventive member is mounted on the outer surface of the transport cylinder (36), the driving of a printing press stops. Also, when an IR lamp (46) of an infrared drying device (47) is turned on and the photoelectric sensor (70) detects that the contamination-preventive member is not mounted on the outer surface of the transport cylinder (36), the driving of the printing press is stopped. With this arrangement, deformation of the contamination-preventive member mounted to protect the cylinder is prevented in a liquid transfer apparatus.