An image-forming apparatus is provided which enables more productive image formation. When an option unit implements a change from a second operation mode that exhibits high power consumption to a first operation mode that exhibits low power consumption while images are being consecutively formed on a plurality of recording materials, an upper limit on power that can be supplied to a fixing section is set higher than that in the second operation mode, and intervals, at which recording materials are consecutively fed, are set narrower than those in the second operation mode.