PURPOSE: To provide the title method intended to feed a gas in high efficiency into a rotator for incubating e.g. cells, so designed that the interior of a rotator with immobilized material therein within a rotary reaction vessel is partitioned into a number of chambers, and a gas is sparged into the respective chambers or some of these chambers.

CONSTITUTION: In a rotary reaction vessel made up of (A) a drum-shaped reaction vessel (a) composed of a shell 1 and end plates 2, 2' on both sides and (B) a rotator (b) rotating within the reaction vessel (a), revolving shafts 12, 12' are externally projected on the respective end plates 11, 11' on both the sides of the rotator (b). The revolving shaft 12', which is a hollow one, is equipped with a solution-ejective pipe 15 with small holes 14 extended inwardly from the end plate 11', and a number of partition plates 16 are projected radially on this pipe 15 to partition the rotator (b) into a number of chambers 18, and each of these chambers 18 is branchedly provided with a gas feed pipe 19, and its end is fitted with a gas-sparging pipe 22 with fine holes on its circumference. With this system, a gas is sparged into the respective chambers 18 or some of these chambers.