To provide a heat-treatment method for annular work-piece and a restricted hardening apparatus using the above method with which the improvement of the size-precision of the inner and the outer diameter of a work-piece, the reduction of a heat-treatment strain and the in-linining of the heat-treatment can be obtained and the annular member can be manufactured at low cost.

The work-piece W is induction-heated and this work-piece W is cooled under state of setting an inner-metallic mold 24 at this inner-diameter surface 23 side, and after becoming ≤500°C restricted on the inner-diameter surface 23 of the work-piece W in the inner-metallic mold 24, the work-piece W is cooled while further restricting both end surfaces 25a, 25b in the width direction of the work-piece W with a first width restricting tool 26. Then, when the temperature of the work-piece W becomes a martensite-transformation starting temperature or lower, the work-piece W is taken out from the inner-metallic mold 24 and thereafter, the outer-diameter surface 41 of the work-piece W is restricted with an outer-metallic mold 42 and also, the width of the work-piece W is restricted with second width restricting tools 43a, 43b.

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