An exposure device includes a rotation driving section that rotationally drives an exposure object; a light irradiation section that irradiates an exposure surface of the exposure object with laser light; a slide moving section secured to the rotation driving section or the light irradiation section, and moving the rotation driving section or the light irradiation section along the exposure surface in a direction crossing a direction of rotation of the rotation driving section; a signal generating section that transmits an analog modulating signal to the light irradiation section in accordance with a rotation synchronization signal from the rotation driving section, the analog modulating signal causing an intensity of the laser light to be changed; and a controlling section that controls movements of the rotation driving section, the slide moving section, and the light irradiation section.