To incinerate marine wastes containing Na, K or the like by fluidizing a fluidized bed with a fluidized bed type incinerator.

A diffusion pipe 3 is arranged at a lower part of a fluidized furnace 1 and a fluidized bed 2 is provided thereabove. A hot air generator 6 is connected to the diffusion pipe 3 and fluidized air sent by a fan 7 is heated by the hot air generator 6. The temperature of the fluidized bed 2 is set near 650°C suitable for incineration only by a heating value of the fluidized air heated by the hot air generator 6. Marine wastes as material 4 to be incinerated are supplied to the fluidized bed 2 from a supplier 5 to be incinerated at the temperature of 650°C. The fluidized bed will cause no sintering even when the Na, K or the like contained in the marine wastes is left on the fluidized bed.