An air emission device (4, 64) for growing a plurality of plants each of which has one stem and a plurality of leaves growing around the one stem comprising: a plurality of air emission units each of which emits an air flow onto new leaves growing on a tip of the stem of each of the plurality of plants, wherein the air of the air flow is adjusted to be air with an adjusted humidity and an adjusted concentration of carbon dioxide and is supplied to the plurality of air emission units from an air supply source through a pipe (20, 70), characterized in that the each of the plurality of air emission units is located at a position close to the each of the plurality of plants and includes a base plate (16, 74), wherein each of a plurality of light emitting devices is provided at an under surface of the base plate and a plurality of air emitting ports (22, 66) in communication with the air supply source is provided at a central portion of the base plate (16, 74); the each of the light emitting devices emits a light onto the each of the plurality of plants and is provided with a stem growth-inhibiting light source facing to the stem at a central position of the plurality of air emitting ports for emitting a stem growth-inhibiting light having a blue component light at high ratio, and with a leaf growth-promoting light source facing to the new leaves at positions outer than the positions of the air emitting ports for emitting a leaf growth-promoting light having a red component light at high ratio; and the air emission device for growing plants further comprises an air emission unit supporting device which adjustably supports the plurality of air emission units in an up/down direction, wherein the air emission unit supporting device supports and locates the each of the air emission units and each of the light emitting devices at a proper position for the same to face to the each of plants. a plurality of air emission units each of which emits an air flow onto new leaves growing on a tip of the stem of each of the plurality of plants, wherein the air of the air flow is adjusted to be air with an adjusted humidity and an adjusted concentration of carbon dioxide and is supplied to the plurality of air emission units from an air supply source through a pipe (20, 70), characterized in that the each of the plurality of air emission units is located at a position close to the each of the plurality of plants and includes a base plate (16, 74), wherein each of a plurality of light emitting devices is provided at an under surface of the base plate and a plurality of air emitting ports (22, 66) in communication with the air supply source is provided at a central portion of the base plate (16, 74); the each of the light emitting devices emits a light onto the each of the plurality of plants and is provided with a stem growth-inhibiting light source facing to the stem at a central position of the plurality of air emitting ports for emitting a stem growth-inhibiting light having a blue component light at high ratio, and with a leaf growth-promoting light source facing to the new leaves at positions outer than the positions of the air emitting ports for emitting a leaf growth-promoting light having a red component light at high ratio; and the air emission device for growing plants further comprises an air emission unit supporting device which adjustably supports the plurality of air emission units in an up/down direction, wherein the air emission unit supporting device supports and locates the each of the air emission units and each of the light emitting devices at a proper position for the same to face to the each of plants.