An inexpensive and highly productive exposure device for directly scanning and exposing a photosensitive material sensitive to at least a UV region, based on digital data. As a motor controller moves an exposure head at a fixed speed in Y direction, image data is read one line of image data, each GLV element of a light modulator array is switched on/off by the read image data, and laser light from a high power light source of the exposure head is switched on/off. A UV-sensitive object to be exposed is exposed in X direction in a number of pixel units that substantially corresponds to the number of the GLV elements. The image data is scanned and exposed by one line in Y direction (main-scan). The motor controller moves a flat stage by one step in X direction (sub-scan). The object to be exposed is imagewise-exposed by repeating such scans.