To provide an image forming device that corrects a position deviation of an optical system in a scanning direction so as to automatically generate an image without distortion and simplifies the position deviation adjustment so as to enhance the job efficiency.

Received image information is stored corresponding to coordinates of a main scanning direction Y equivalent in a read width direction of the image and of a sub scanning direction X orthogonal to the direction Y, referencing the coordinates in the main scanning direction Y and the sub scanning direction X corresponding to the stored image information calculates a tilt in the image information and controlling the read address of the image information stored in an image memory 302 on the basis of the calculated tilt of the image information corrects an offset of the coordinate of the image information.