To provide a continuous heat treatment furnace in which temperature difference produced in a direction perpendicular to a traveling direction of a heat treatment object is reduced, and from which a high quality heat treatment article can be obtained.

The continuous heat treatment furnace 10 includes a furnace body 12 including an inlet part 12A, a heating part 12B, and an exit part 12D, a muffle 14 disposed in the heating part 12B, a heater part 16 for heating the heat treatment object via the muffle 14, and a belt 24 passing by a driving means, in the muffle 14. A sheath S housing the heat treatment object is disposed on the belt 24, the sheath S is carried into the furnace body 12, and thus heat treatment to the heat treatment object is continuously performed. The heating part 12B includes a heat rising area 12b1 and a heat storage area 12b2, the heater part 16 includes a metallic heaters 20a, 20b, and in the heat rising area 12b1, width w1 of the metallic heaters 20a, 20b when viewed in a direction perpendicular to the traveling direction of the belt 24 is formed same as width w2 of the sheath S.