PURPOSE: To provide a conveying device guaranteeing that a sheet is completely locked to a conveying cylinder when it passes in front of a detection system without a danger that printing on the sheet is damaged.

CONSTITUTION: A conveying cylinder 1 is provided with a bar-like sheet clamp 2 for grasping the leading edge part of a sheet 3. A calibrating strip 6 fitted to the face of the cylinder 1 in a movable system, adjusting mechanism 12-15 for adjusting the strip 6 for setting a distance from the strip 6 to the cylinder 1 in the operation position to a value decided so that the sheet 3 hugs the cylinder 1 and a mechanism 5 for intermittently lifting the strip 6 when the sheet clamp 2 passes below the strip 6 for avoiding collision between the strip 6 and the sheet clamp 2 are installed near a detector 4.