an image forming section that forms an image on a sheet, based on image data of a job;

a sheet ejection tray on which to stack sheets having been formed with an image;

a shifting unit that shifts and stacks the sheets onto the sheet ejection tray;

an operation section to set an image forming condition of the job;

a control unit to control image forming;

a sort mode to operate the shifting unit;

a double sided mode to form an image on both sides of a sheet; and

a single sided mode to form an image on a single side of a sheet,

wherein, the operation section comprises a cuttable sheet quantity input section to input a cuttable quantity of sheets as an image forming condition, and in a case where an image forming order starts with an Nth page and ends with a first page, N denoting a page quantity in the image data,

if a quantity of image forming sheets in the job is within an inputted cuttable sheet quantity, the control unit performs control to form an image based on a composite image of image data and a cut guide attached to the image data only on a last image forming page; and

if the quantity of image forming sheets in the job exceeds the inputted cuttable sheet quantity, the control unit performs control to:

select the sort mode;

set a quantity of shift-ejection sheets within the cuttable sheet quantity and operate the shifting unit;

shift and stack sheets onto the sheet ejection tray as sheet stacks each of which being in the quantity of shift-ejection sheets; and

form an image based on a composite image of image data and a cut guide attached to the image data only on a last image forming page of each shifted sheet stack.