PROBLEM TO BE SOLVED: To provide a weeder for paddy field, with which a weeding apparatus is arranged in close to a wheel (axle) and the raising operation of the weeding apparatus by a handle is lightened during a rotation at a field end.SOLUTION: Rotors 40 are brought into contact with the surface of a paddy field and rotated while driving and running the wheel 2 composed of a monowheel by an engine 4 to weeds at an intrarow spacing and in close to a hill. Two pairs of rotors for weeding the intrarow spacing of right and left planting rows U1 and U2 of an interrow space B1 on which the wheel 2 runs are arranged at a fixed interval in the longitudinal direction on each side of the planting row, both rear-side rotors 401r and 402r are positioned behind the wheel 2 and front side rotors 401f and 402f are positioned so as to overlap with the wheel 2 on the side view.COPYRIGHT: (C)2007,JPO&INPIT【課題】除草装置を車輪(車軸)に近づけて配置することを可能とし、圃場端での回向時、ハンドルによる除草装置の持ち上げ作業を軽くした水田用除草機を提供する。【解決手段】1輪からなる車輪2をエンジン4により駆動して走行しつつ、ロータ40を田面に接触して自転し、株間及び株ぎわの雑草を除草する。車輪2が走行する条間B1の左右の植付条U1,U2の株間を除草する2対のロータは、植付条を挟んで前後方向に所定間隔を隔てて配置され、かつ後側のロータ401r,402fが両方とも車輪2の後方に位置すると共に前側のロータ401f,402fが側面視車輪2とオーバラップするように配置される。【選択図】図2