An image forming apparatus includes an image forming portion, a fixing portion, a temperature detecting portion, a measuring portion, a storing portion, and a controller. The controller is capable of setting a case that a start of feeding of a recording material is permitted after a lapse of a predetermined time need to measure a temperature rising rate of the fixing portion and a case that the start of feeding of the recording material is permitted, depending on a value relating to the temperature rising rate stored in the storing portion, at timing before the lapse of the predetermined time.