In an exposure device comprising a laser controller that is configured as a circuit board capable of independently being changed, and that controls the emission of laser light from a laser emitter emitting laser light on receipt of an instruction for control given from a main controller responsible for overall control of the operation of the exposure device, error control information that is obtained in advance with regard to the circuit board and controls variations of a controlling factor due to a circuit error of the circuit board is stored into a memory provided to the laser controller prior to the provision of the circuit board to the exposure device. On receipt of an instruction for control given from the main controller to cause the emission of laser light in a predetermined amount of light, the laser controller determines a condition of emission of laser light based on the error control information stored in the memory to cause the laser emitter to emit laser light under the condition of emission.