A fixing device for heating and fixing an unfixed image to a record member bearing the unfixed image, including a heating roller, a backup member, and a current transmitting units. The heating roller includes a core roller, and a resistance heating member which is formed on the core roller and generates heat when a current is transmitted thereto through the current transmitting units, and is rotatably carried at opposite ends of the core roller by bearing units. The current transmitting units are arranged at positions opposed to the bearing units. The current transmitting unit includes a current receiver member and a current supply member. At mutual contact surfaces of them, the current receiver member has a concave section, and the current supply member has a convex section. The outer periphery circle of at least one side surface of said current receiver member has a radial difference of 6 mm or more with respect to an outer periphery circle of the heating roller at a sheet passing region. The heating roller has dust mevement restricting grooves.