This invention has an object to process color balance adjustment at high speed in an image forming apparatus without depending on different feeding speeds for different printing materials. To accomplish this, an image forming apparatus of the invention detects color balances while a printing material on which toner patches are formed is fed on a second feeding path. Since images are formed on different types of printing materials at different feeding speeds, the image forming apparatus of the invention processes color balance adjustment at high speed without depending on the feeding speed at the time of image formation by switching the feeding speed on the feeding path.