PURPOSE: To determine the degree of skew of a sheet by detecting the edge position of the sheet in the feed direction using two separate sensors in the direction perpendiclar to the feed direction of the sheet.

CONSTITUTION: A printing device is capable of detecting the feed direction of a sheet 15 and the end position of the sheet in said direction using two different sensors 13, 14 in the feed direction and the vertical direction of the sheet 15 as well as controlling the feed amount of the sheet and a speed at which the sheet is fed. The difference in time required for the sensor to detect the presence of the sheet from a state 'the non-presence of the sheet' when the sheet is introduced and the difference in time required for the sensor to change from the state 'the presence of the sheet' to 'the non-presence of the sheet' are compared using the two different sensors. Thus the degree θ of a skew of the sheet can be detected by calculating the comparison results including the feed speed and feed amount of the sheet.