Abstract: It is intended to provide a plant growth system wherein light sources are located close to plants so as to efficiently ensure a sufficient amount of light for the plants to grow and simultaneously ensure air flow, thereby providing a favorable growth environment for the plants. In a plant growth chamber (1), there are provided multiple shelf parts (32) for irradiating the plants with light for the growth, a cover (332) surrounding the light sources (331) wherein multiple ventilation bores (332x) are formed on a plant-facing face (3321) of a transparent light-permeable wall, an air inlet (31a) that opens in the space within the cover (332) for sucking the air in the space, and a circulation channel (L1) that cools down the air sucked through the air inlet (31a) and blows out the sucked air into the plant growth chamber (1).