An image forming apparatus includes a plurality of cartridges containing toners, each cartridge including a storage element that stores a type of thermal characteristic information of the toner contained therein, and a reading portion configured to read the type of thermal characteristic information. A fixing portion thermally fixes a toner image, formed by a plurality of toners of different colors contained in the cartridges, respectively, onto a recording material, and a control portion controls the fixing portion by switching a thermal fixing condition in accordance with a combination of the types of the thermal characteristic information read by the reading portion, the thermal fixing condition being a condition that prioritizes the performance of fixing, to a recording material, a toner, of the toners that form the toner image, that is transferred first to the recording material, from among the plurality of toners of different colors.