PURPOSE: To precisely adjust toner density without idly increasing toner consumption by changing measuring interval corresponding to the stability of the toner density in an electrophotographic recording device.

CONSTITUTION: A reference toner image is formed on a photosensitive body 12 and the toner density of the reference toner image is measured by a sensor, and toner supplying interval to a developing chamber 14a is changed according to a measured result, and then, reference toner image forming interval is changed by comparing the measured result with a previous measured result. Then, similarly, recording is continuously performed while the toner is supplied at the changed supplying interval and the reference toner image is formed again on the photosensitive body 12 at a changed forming interval. Hereafter, measuring the toner density of the reference toner image, changing the toner supplying interval, changing the reference toner image forming interval, supplying the toner and forming the reference toner image are similarly repeated.