PROBLEM TO BE SOLVED: To obtain an aeration device which efficiently and uniformly supplies a large amount of fine bubbles into a tank as a whole together with a water flow, in an aeration tank, an aqueous culture tank and a culture tank.SOLUTION: This pump aeration device constituted of a cylindrical multiblade impeller-type through-flow pump (cross-flow pump) having a fine bubble generation mechanism is arranged in the aeration tank, the aqueous culture tank or the culture tank, the uniform wide-width water flow is supplied into the tank together with the fine bubbles, and effective aeration is performed. The fine bubbles can be obtained from an air dispersion hole which is protrusively formed at a hollow rotation shaft of an impeller and from a porous material, or from an air dispersion generator arranged at the suction side or the discharge side of the pump.
