To provide a boom spraying apparatus that enables effective spraying and multipurpose liquid chemical spraying to the crops having a ground height exceeding 2 m while stably maintaining a weight balance during working, has a low cost and high storage capability of a boom, is convenient and has a simple structure.SOLUTION: A boom spraying apparatus 1 includes: a riding traveling machine body 10 equipped with a tank 11； a front boom device 20 mounted in the front end of the traveling machine body, and making the height of the boom be lower than the setting height； and a rear boom device 30 mounted in the rear end of the traveling machine body, and making the height of the boom be higher than the setting height. The rear boom device enables setting the boom height at the position higher than the uppermost position of the tank, and has the gravity center of the traveling machine body including the tank being present between the front wheel shaft and the rear drive wheel of the traveling machine body regardless of a change of a storage amount of the tank.SELECTED DRAWING: Figure 1【課題】作業中の重量バランスを安定的に維持しながら、地上部高さが２ｍを超える程度の作物に対して効果的な散布と多用途の液剤散布が可能な低コストで且つブームの収納性をが高く、使い勝手が良く簡易な構造のブーム散布装置を提供する。【解決手段】ブーム散布装置１は、タンク１１が搭載された乗用式の走行機体１０と、走行機体の前端部に装着され、ブームの高さを設定高さより下方にしたフロントブーム装置２０と、走行機体の後端部に装着され、ブームの高さを前記設定高さより上方にしたリアブーム装置３０とを備え、リアブーム装置は、タンクの最上位置より高い位置にブーム高さを設定可能であり、タンクの貯留量の変化に拘わらず、タンクを含む前記走行機体の重心が、走行機体の前輪軸と後輪軸の間にある。【選択図】図１
