A fixing device includes a fixing member; a pressing member to be pressed against the fixing member; a first heating member for heating the fixing member; a second heating member for heating the fixing member supplementarily; and a third heating member for heating the pressing member. The first heating member has a first rated output; the second heating member has a second rated output; and the third heating member has a third rated output. The first rated output is greater than the second rated output, and the second rated output is equal to or greater than the third rated output. Further, the second heating member and the third heating member are connected in series relative to a voltage applying device or a power source.