PURPOSE: To form an image at the prescribed position of a recording media out of specification by providing an input means to input the length to be transported of a recording media out of specification in size and a control means of the picture forming process in accordance with the carrier length to be transported.

CONSTITUTION: When the length to be transported of the recording media out of specification in size is inputted from a displaying/operating part 26, based upon the input data of the length to be transported from a displaying/operating part 26, a control part 40 chages over respective controls of a paper transporting driving system 43 and a picture forming action part 44, and a picture forming process control, the transporting control of the recording media and a jam detecting control are executed. Consequently, even for the recording media out of specification in size, the picture is formed without fail efficiently at the prescribed position of the recording media.