In a plant culture apparatus, plants being cultured are accommodated in a body. A culture bed is arranged within the body for culturing the plants. An illuminating device is arranged within the body for emitting a light to the plants on the culture bed. A gas-conditioning device is mounted to the body for recirculating gas therethrough. The illuminating device includes a lighting unit for emitting ultraviolet rays to the plants, and a transducing unit arranged below the lighting device for transducing the ultraviolet rays emitted from the lighting unit, to visible radiation. The transducing unit has long-wave absorbability and is formed by a plate element having its entire surface which is coated with phosphor.
