An image forming apparatus includes a controller to set one of a first print mode, in which, after starting printing on a first number of sheets per unit time, a printer decreases a number of sheets on which the printer performs printing per unit time from the first number of sheets per unit time so as to avoid a rise in temperature of a fixing device to a predetermined temperature value, and a second print mode. In the second print mode the printer performs printing on a second number of sheets per unit time without changing, based on a rise in temperature of the fixing device, a number of sheets on which the printer performs printing per unit time, where the second number is smaller than the first number.