To provide a divided exposure device which is made compact by suppressing the number of components increased according to the number of scanning systems by making the components commonly usable when the exposure device has plural scanning systems, executes drawing with high resolution by increasing a beam diameter and is capable of correcting the misalignment of scanning lines in a sub-scanning direction.

This divided exposure device comprises a light source which emits one laser beam, a transmission type diffraction element which splits the one laser beam emitted from the laser beam source to plural beams, an optical modulation element which modulates the plural laser beams respectively in accordance with drawing data, a beam expander which expands the respective beam diameters of the plural laser beams and respective hologram scanning systems on which the expanded laser beams are made incident. Further, the device has an optical deflector and a beam detector on an exposure table and executes the correction in the sub-scanning direction of the scanning lines by controlling the optical scanner in accordance with the misalignment quantity of the scanning lines detected by the beam detector.