PURPOSE: To provide a method for roasting a granular material to be treated in which the amount of evaporated moisture per unit time can be increased, the efficiency of a roasting step is improved and the contribution can be made to improvement in quality of the product.

CONSTITUTION: The objective method for roasting a granular material to be treated is to carry out a hot-air fluidized bed roasting step for housing the granular material 2 which is an object of roasting to be treated in a roasting chamber 3 equipped with a flow rectifying plate 15 in the bottom thereof, feeding hot air from the lower part of the flow rectifying plate 15 into the roasting chamber 3 and heat-treating the granular material 2 to be treated in a fluid state and a microwave roasting step for irradiating the granular material 2 to be treated in the fluid state with microwaves and heating the granular material 2 to be treated with the microwaves. In this case, the objective apparatus for roasting is equipped with the roasting chamber 3 provided with the flow rectifying plate 15 in the bottom thereof, a hot air feeder 13 for feeding the hot air from the lower part of the flow rectifying plate 15 into the roasting chamber 3 and heating the granular material 2 to be treated in the fluid state and a microwave heater 12 for irradiating the granular material 2 to be treated with microwaves and heating the granular material to be treated therewith.