A fixing device, including a fixing rotary body including a first heat source, a pressing rotary body including a second heat source, and a control device configured to cause, at a time of warm-up of the fixing device, the fixing rotary body to rotate while causing at least one of the first heat source and the second heat source to generate heat, and to allow, after a surface temperature of the fixing rotary body has risen to a preselected warm-up temperature, a sheet pass or a printing to be executed and cause, if a sheet pass is not executed, the fixing rotary body to rotate for a preselected period of time.