To provide a planting/seeding machine having a ground preparation device in which a maintainability of a detection system for detecting a height from a ground surface of rice field to the machine is improved.SOLUTION: The present invention includes: a work device 5 supported to a machine body via a link mechanism 3 connected to a rear part of the machine body in a vertically swinging manner； a hydraulic cylinder which drives the link mechanism 3 to be lifted and lowered； a control valve for supplying/discharging working oil to/from the hydraulic cylinder； and a grounding body 9 that comes into contact with and follows along the ground surface of rice field G. Sensing mechanism 85, 86 are connected between the control valve and the grounding body 9 so as to mechanically extract a vertical motion of the grounding body 9 and transmit to the control valve. A ground preparation device 53 is provided between the machine body and the work device 5, and provided with: a lift/lower mechanism 81 which supports the ground preparation device 53 so as to be freely lifted and lowered； and an electric actuator 56 which drives the ground preparation device 53 so as to be freely lifted and lowered.SELECTED DRAWING: Figure 3【課題】整地装置を備えた植播系作業機において、田面から作業装置までの高さの検出系のメンテナンス性の向上を図る。【解決手段】機体の後部に上下揺動自在に連結されたリンク機構３を介して機体に支持された作業装置５と、リンク機構３を昇降駆動する油圧シリンダと、油圧シリンダに作動油を給排操作する制御弁と、田面Ｇに接地追従する接地体９とを備える。接地体９の上下動を機械的に取り出して制御弁に伝達するように、制御弁と接地体９とに亘って感知機構８５，８６が接続される。機体と作業装置５との間に整地装置５３が備えられて、整地装置５３を昇降自在に支持する昇降機構８１と、整地装置５３を昇降駆動する電動アクチュエータ５６とが備えられる。【選択図】図３
