PROBLEM TO BE SOLVED: To provide a paddy field working machine in which a groove-cutting body can be disposed at the center in the lateral direction of a machine body while facilitating balance of the right and left weight of the machine body.SOLUTION: A support rod 55 in the lateral direction of the machine body is connected from both lateral ends of a drive case 19 in the lateral direction of the machine body over extension end sides of a lateral pair of transmission cases 26, 26 for extending respectively. The groove-cutting body 14 for forming drain grooves on a field surface is disposed at the center in the lateral direction of the machine body to be supported by the support rod 55.COPYRIGHT: (C)2013,JPO&INPIT【課題】機体の左右重量をバランスさせ易くしながら、溝切り体を機体横方中央部に配備できる水田作業機を提供する。【解決手段】機体横向きの駆動ケース19の両横端部から各別に延出する左右一対の伝動ケース26,26の延出端側にわたって機体横向きの支持杆55を連結してある。圃場面に排水溝形成する溝切り体14を、機体横方向での中央部に配置して支持杆55に支持させてある。【選択図】図7