PROBLEM TO BE SOLVED: To perform sinter so that sintering is not performed at short cycle time.SOLUTION: Provided is the sinter method of powder compact, for passing a workpiece through a sintering zone, first slow cooling zone, second slow cooling zone, and cooling zone in the order. In the first slow cooling zone, atmospheric temperature is held at first slow cooling temperature lower than an eutectic point of the material of the workpiece, the workpiece is passed through the first slow cooling zone for lowering of the workpiece to temperature lower than the eutectic point. In the second slow cooling zone, atmospheric temperature is held at second slow cooling temperature lower than the first slow cooling temperature and higher than a Ms point of the material of the workpiece, the workpiece is passed through the second slow cooling zone for lowering the temperature of the workpiece to a temperature range higher than the Ms point and holding the temperature range. In the cooling zone, the temperature of the
