To provide a fluidized bed device of a simplified structure attained by eliminating a need for installing a partition in a fluidized bed container, capable of solving problems associated with its abrasion and cost, of making the fluidizing velocity of fluidizing media in the fluidized bed container uniform, of eliminating a dead space therein, and of extending the retention time of the fluidizing media.

The fluidized bed device 3 including a fluidized bed container 1 in which a fluidized bed 2 of fluidizing media is formed by a gas, is characterized in that the width of a feed port 4a of a feed nozzle 4 connected to the upstream end in the flow direction of the fluidizing media in the longitudinal direction of the fluidized bed container 1 is made equal to the width of the fluidized bed 2, and the width of a discharge port 5a of a discharge nozzle 5 connected to the downstream end of the flow direction of the fluidizing media in the longitudinal direction of the fluidized bed container 1 is made equal to the width of the fluidized bed 2.