an image forming portion including (1) an image bearing member configured to bear an image and (2) a transfer portion configured to transfer the image formed on said image bearing member to a sheet;

a first correcting portion including (1) a registration roller pair for correcting oblique movement of the sheet, the registration roller pair being configured to nip and feed the sheet and being movable in a widthwise direction perpendicular to a sheet feeding direction, and (2) a first detecting means for detecting a sheet position with respect to the widthwise direction, wherein said first detecting means comprises a sensor, and wherein said first correcting portion corrects a position of the sheet in the widthwise direction by said registration roller pair on the basis of a detecting result of said first detecting means;

a second correcting portion including (1) a reversing roller pair for reversing the feeding direction of the sheet, the reversing roller pair being configured to nip and feed the sheet and being movable in the widthwise direction and (2) a second detecting means for detecting the sheet position with respect to the widthwise direction, wherein said second detecting means comprises a sensor, and wherein said second correcting portion corrects the position of the sheet in the widthwise direction by said reversing roller pair on the basis of a detecting result of said second detecting means; and

a controller configured to control said first correcting portion and said second correcting portion,

wherein said controller, in a case in which the sheet is fed to said transfer portion, to form the image on the sheet, via said first correcting portion from said second correcting portion, (1) causes said second correcting portion to correct the position of the sheet to a second position, and (2) causes said first correcting portion to correct the position of the sheet to a first position to be aligned with the image transferred in said transfer portion, and

wherein, when a previous sheet has been moved to a third position of said second detecting means by said reversing roller pair and then the previous sheet is detected at a previous sheet position by said first detecting means, the second position is a position offset from the third position of said second detecting means toward an opposite side to a direction where the previous sheet position detected by said first detecting means is shifted from the first position.