To stably prevent a start staggering of image exposure, by a plurality of laser beams.

The image formation apparatus is configured to detect a reference point of line scanning of each beam of the plurality of laser beams by synchronous sensors 45, 52, 49 and 44, generate synchronizing signals M, C, Y and K corresponding to respective laser beams, set a starting timing of image exposure corresponding to each laser beam on the basis of each synchronizing signal, form each latent image on photoreceptors 111M, 111C, 111Y and 111K, develop the images by developing devices 120M, 120C, 120Y and 120K, and transfer sensible images directly or indirectly via an intermediate transfer member to the same paper. The image formation apparatus widens a lag between a plurality of synchronizing signals M and C by delaying the synchronizing signal C which has an occurrence timing close to that of the reference synchronizing signal M by a delaying means 79, and sets the starting timing of image exposure FGATE-C=H on the basis of the lag.