A fixing device is provided with an endless fixing belt; a heating roller for heating the fixing belt; a fixing roller that has a shaft and extends the fixing belt between the fixing roller and the heating roller; a pressure roller for pressurizing the fixing roller via the fixing belt; and a deviation preventing member that is provided on the shaft of the fixing roller and suppresses moving of the fixing roller in a shaft direction. The fixing roller has an end portion with high hardness and an end portion with low hardness along the shaft direction of the fixing roller. The end portion with high hardness is in contact with the deviation preventing member.