The preferred embodiments provide a copying machine having a variable magnification copying function which includes a circuit for detecting or entering the length of each side of an irregular-sized document and a calculating circuit for operating the magnification ratio using the length of each side of the irregular-sized document and the length of each side of the set copy paper; a copying machine having a picture position setting function which includes a second operating circuit which calculates the product of the length of the lateral side of a document and the above-mentioned magnification ratio and further determines the difference between this operation result and the length of the lateral side of the copy paper; a display circuit for displaying this operation result as an allowable blank range, a circuit for distributing the blank spaces to the left and right sides, the allowable blank range displayed by this display circuit and a circuit for controlling the timing of copy paper feeding in response to the amount of margin to be allocated.