PURPOSE: To reduce the flowing out of an air layer heated by a heat source inside a heating roller therefrom, in the fixing unit of a printer, a copying machine, etc.

CONSTITUTION: This thermocompression type fixing unit is constituted of a hollow heating roller 2, a pressure roller 3 in press-contact therewith and the heat source 1 disposed inside the heating roller 2 and integrally provided with two shield plates 11 shielding the opening parts of both ends of the heating roller 2. Thus, the flowing out of the air layer inside the heating roller 2 can be reduced as in the conventional case using a shield plate as a separate part. Further, since the shield plates are integrated with the heat source 1, effects such as reduction in the number of parts and in assembly man-hours and the prevention of the accident of the coming off of the shield plate can be obtained.