An fixing device comprises a heating member, a first heater, a second heater, and the heating member, a first temperature detector, a second temperature detector, and a controller configured to control energization to the first heater and the second heater based on an energization pattern for each control period. In a case where a length of the control period is T, a length of a period during which a first continuous energization control is T1, and a length of a period during which a second continuous energization control is T2, when a first condition represented by T1+T2