PROBLEM TO BE SOLVED: To prevent a uniform spraying within the spraying width from being disturbed even when adjusting the boom length in a boom spraying device which adjusts the boom length to arbitrarily control the spraying width. SOLUTION: The boom spraying device includes a plurality of booms in which a plurality of spraying nozzles are arranged at equal intervals, and a boom length is adjusted by making the overlapping state along the longitudinal direction of the plurality of booms variable. A length adjusting mechanism and a control unit 24 that drives and controls the boom length adjusting mechanism to expand and contract the boom length in units of intervals at which the spray nozzles are arranged. [Selection diagram] Fig. 4【課題】ブーム長さを調整して散布幅を任意に制御するブーム散布装置において、ブーム長さの調整時にも散布幅内での均一散布が妨げられないようにする。【解決手段】ブーム散布装置は、等間隔で複数の散布ノズルが配備された複数のブームを備え、複数のブームの長手方向に沿った重なり状態を可変にすることでブーム長さを調整するブーム長さ調整機構と、ブーム長さ調整機構を駆動制御して、ブーム長さを散布ノズルの配備間隔単位で伸縮させる制御部２４とを備える。【選択図】図４
