PURPOSE: To feed securely CO2-containing air to a tank for photosynthesis, by jetting CO2-containing air through an air jet inlet to a rotary disc to rotate it, feeding the CO2-containing air to a reaction tank for photosynthesis.

CONSTITUTION: A great number of capillary radiator groups 10 are set in parallel in the reaction tank 1 for photosynthesis, and the rotary disc 50 having the air jet nozzle 51a in the horizontal direction and the air jet nozzle 52a in the vertical direction is arranged at the bottom side of the light radiator groups. CO2-Containing air is jetted through the air jet nozzle 51a to the rotary disc, to rotate it, and the CO2-containing air is fed through the air jet nozzle 52a to the reaction tank 1. Namely, when the rotary disc is used instead of an existing impeller, balance of all members can be kept well, and the CO2-containing air can be fed to the reaction tank 1 securely and stably.