To provide a reacting furnace suitably applied in manufacturing powder of magnetic material by using a HDDR (hydrogenation decomposition desorption recombination) method, and to provide a method of manufacturing the powder for magnetic material.

This reacting furnace 1 is applied in manufacturing the powder for magnetic material by HDDR reaction. The reacting furnace 1 includes an outer container 10, a body-side cooling medium passage 10Bc and a cover-side cooling medium passage 10Cc as an outer container cooling means, an inner container 20, an inner container driving device 18 as an inner container driving means, a heater 2, a gas inlet 12I and a gas outlet 12E, and an air guide body 15 as a gas flow control means.