PROBLEM TO BE SOLVED: To perform spraying outside a spraying scheduled area or spraying within a spraying scheduled area even in various situations in a boom spraying device that variably adjusts a spraying width by adjusting a boom length so as to match a boundary line of the spraying scheduled area. Prevent leaks. SOLUTION: The boom spraying device includes a control unit 20 that controls a spraying width based on position information of a machine body based on a GPS signal, and the control unit 20 sprays a boundary line of a preset spraying area 24 and spraying. The boom length control unit 26, which controls the length of the boom so that the ends of the width coincide with each other, and the boundary of the preset spraying area 24, which corresponds to the end of the spraying width, are attached to the boom. A nozzle opening/closing control unit 27 that individually controls opening/closing of a plurality of spray nozzles arranged at set intervals. [Selection diagram] Fig. 5【課題】散布予定領域の境界線に合わせるようにブーム長さの調整によって散布幅を可変に調整するブーム散布装置において、様々な状況においても、散布予定領域外の散布や散布予定領域内の散布漏れなどを抑止する。【解決手段】ブーム散布装置は、ＧＰＳ信号に基づく機体の位置情報に基づいて散布幅を制御する制御部２０を備え、制御部２０は、予め設定されている散布予定領域２４の境界線と散布幅の端が一致するように、ブームの長さを伸縮制御するブーム長さ制御部２６と、予め設定されている散布予定領域２４の境界線と散布幅の端が一致するように、ブームに設定間隔で配置された複数の散布ノズルを個別に開閉制御するノズル開閉制御部２７とを備える。【選択図】図５
