An image fixing apparatus has a first rotatable member heated by a first heater and a first temperature detecting element for detecting its temperature; a first controller for controlling electric supply to the first heater to maintain a detected temperature of the first temperature detecting element at a first target temperature; a second rotatable member heated by a second heater and forming a fixing nip with the first rotatable member; a second temperature detecting element for detecting a temperature of the second rotatable member; a second controller for controlling electric supply to the second heater to maintain the detected temperature of the second temperature detecting element at a second target temperature; and a phase controller for controlling electric energy supply phase so as to avoid overlapping of a phase of an electric power supply to the first heater and a phase of an electric power supply to the second heater.