The present invention does not require a new pipe, there is provided a CO 2 spraying device capable inexpensive and easily CO 2 application. A through the earlier three-way valve V of the water supply line 2 and the supply path 1 of CO 2 is connected to the irrigation pipe 3, when the CO 2 application is spraying the CO 2 from irrigation pipe 3, irrigation at the time of irrigation pipe from 3 spraying water. It may be performed automatically in accordance with the data of this changeover from CO 2 sensor. In addition, the irrigation pipe 3 in the commercially available porous pipe, as well as support by flying this porous pipe from the ground, it may be placed in the vicinity of the back of the pores of the leaves of the plant in the cultivation facility.【課題】新たな配管を必要とせず、安価で簡便にCO2施用ができるCO2散布装置を提供する。【解決手段】CO2の供給路1と給水路2の先に三方弁Vを介して潅水パイプ3を接続し、CO2施用時は潅水パイプ3からCO2を散布し、潅水時は潅水パイプ3から水を散布する。この切換をCO2センサからのデータに従い自動で行うとよい。また、前記潅水パイプ3を市販のポーラスパイプにして、このポーラスパイプを地面より浮上させて支持すると共に、栽培施設内の植物の葉の裏の気孔の近傍に配置するとよい。
