Image forming apparatus

An image forming apparatus adapted to form an image on a sheet by an image forming portion, and thereafter detect the presence or absence of an abnormality of the sheet on which the image has been formed, said image forming apparatus comprising:

• abnormality detecting means for detecting the abnormality of the sheet;
• an abnormal sheet containing portion for containing therein the sheet of which the abnormality has been detected by said abnormality detecting means;
• a normal sheet containing portion for temporarily containing therein a normal sheet of which the abnormality has not been detected by said abnormality detecting means;
• and
• a controlling portion for controlling said image forming portion so that the abnormal sheet of which the abnormality has been detected by said abnormality detecting means may be contained in said abnormal sheet containing portion, and that an image formed on the abnormal sheet may be formed on a predetermined subsequent sheet subsequent to the abnormal sheet,
• wherein said controlling portion controls so that the normal sheet between the abnormal sheet and the predetermined subsequent sheet may be contained in said normal sheet containing portion after the abnormal sheet is contained in said abnormal sheet containing portion, and the normal sheet contained in said normal sheet containing portion may be delivered after the predetermined subsequent sheet has been delivered.