An apparatus for wet process exhaust (3) gas desulfurization comprises a spreading portion for spreading absorbent slurry (9) including calcium compound, a absorbing tower for bringing the absorbent slurry spread from the spreading portion into contact with exhaust gas (3) including sulfur oxides from opposite directions so as to absorb the sulfur oxides in the exhaust gas (3) into the absorbent slurry (9), a slurry tank (11) disposed below of the absorbing tower for receiving the absorbent slurry from the absorbing tower, a stirrer for stirring and forwarding the absorbent slurry radial inwardly, the stirrer being in an axial flow type one having a propeller, and circular system for circulating the absorbent slurry from the slurry tank to the spreading portion. The apparatus further comprises a plurality of nozzles for feeding oxidizer gas including oxygen into the absorbent slurry from a backside of the propeller towards a periphery thereof uniformly with respect to a circumferential direction, thereby bubbling the oxidizer gas finely around the propeller.