To improve productivity while reducing the burden of an operator, and improve the accuracy of sheet quality inspection.

A sheet quality inspection portion 5 for conducting quality inspection of a sheet 2 is arranged upstream of an offset printing part 6 for printing a print image on the sheet 2 in a direction in which the sheet is conveyed. If a sheet is determined to be abnormal in the sheet quality inspection portion 5 and a plurality of such abnormal sheets have been fed consecutively, feed of the sheets from a sheet feed device 4 is stopped and a rubber cylinder 36 of the offset printing part 6 is extracted and the abnormal sheets are controlled to be delivered to an abnormal sheet pile 9.