A complex fluidized bed type apparatus for reducing a fine iron ore, and a method therefor, are disclosed in which the reactivity of the fine iron ore particles, the gas utilization degree and the gas consumption rate are most efficiently, thereby reducing a fine iron ore of a wide particle size distribution in an optimal manner. The apparatus includes first (100) and second (200) fluidized bed furnaces and a cyclone (300), with a gas distributor being installed in the lower portion of each of the furnaces (102, 202). The fine iron ore is separated into coarse and medium/fine iron ore particles within the first fluidized bed furnace (100) which is installed within a freeboard zone within the second fluidized bed furnace (200). A second iron ore discharging hole (105) is connected through a conduit (106) into a lower portion of the second fluidized bed furnace (200). The cyclone (300) is connected from its bottom through a conduit (305) into the lower portion of the second fluidized bed furnace (200).