To provide an image forming device and an image forming method capable of reducing the time required for entire image formation.

After a motor is normally rotated and an illumination lamp is moved to irradiate an original, an operatar control panel displays 'finishing reading the original' interlocked with a turning-off instruction signal to the illumination lamp or a reverse rotation starting instruction signal to the motor transmitted from a control part, so that the first original is not replaced when the second original can be copied as shown in the conventional manner but the original is immediately replaced by an operator when the irradiation or the scanning of the first original is finished and copying is started when the second original can be copied, whereby the time spent for the entire image formation is saved.