PURPOSE: To roast coffee beans uniformly without losing fragrance and flavor, by heating the coffee beans in a closed state, and heating the coffee beans in an opened state.

CONSTITUTION: A given amount of coffee beans is charged from an opened opening and closing valve 17 into a rotating roaster 5, and the valve 17 is closed. On the other hand, inlets 9 and 9 of a compartment 4 are closed to close an air discharge outlet 24 and a hot air outlet 14 of a passage 15. A rotating change-over valve 30 is operated to connect an air discharge passage 28 to an air discharge return passage 31, and a burner 2 of a combustion chamber 3 is ignited to rotate and drive the roaster 5. Hot air produced in the chamber 3 is passed through a roasting chamber 1, the passage 28 and the return passage 31 and returned to the chamber 3, and the hot air in the chamber 3 is partially passed through an air discharge deodorizing passage 34, deodorized and released to the air. On the other hand, fresh air is passed through a fresh air intake passage 36 to flow in the chamber 3. Thus, coffee beans having various tastes can be produced by adjusting the respective heating time in the first stage of heating the coffee beans in a closed state and the latter half stage of heating the coffee beans in an opened state.