Provided is printing apparatus which includes: a light-emitting device array and a photoconductor, wherein the light-emitting device array includes the light-emitting devices of the number greater than the number of pixels of a single line of the print image, data of the single line of the print image are allocated to a portion of the light-emitting devices in the light-emitting device array, and in a period in which exposure of the photoconductor is halted, the light-emitting devices to which the data of the single line of the print image are allocated are shifted in position in the light-emitting device array.