To provide a combine capable of surely holding a use state of a waste straw processor and reducing troublesomeness in inspection and maintenance of a thresher and the waste straw processor.SOLUTION: A combine comprises: a thresher 9 for performing threshing processing of reaped grain culm； a waste straw processor 12 jointed to a rear end part of the thresher 9, rotatably supported to the rear end part rotatably around a vertical shaft, and which can be switched between a use state in which the rear end part is closed and shredding processing can be performed, and an open state for opening the rear end part to a rear side of a machine body； and a lock mechanism 40 for holding the position of the waste straw processor 12 to the position in the use state. The lock mechanism 40 has a first engagement part 41 provided on the thresher 9, a second engagement part 42 provided on the waste straw processor 12 and can be engaged to the first engagement part 41. The combine has an operation tool 44 for switching a state of the first and second engagement parts 41, 42 between an engagement state and non-engagement state, and a holding mechanism 45 capable of holding the position of the operation tool 44 in the engagement state.SELECTED DRAWING: Figure 7【課題】排藁処理装置の使用状態が確実に保持されつつ、脱穀装置や排藁処理装置の保守点検における煩わしさが軽減されたコンバインを提供する。【解決手段】刈取穀稈を脱穀処理する脱穀装置９と、脱穀装置９の後端部に連接し、後端部に縦向軸回りに回動可能に支持され、後端部を閉塞して細断処理が可能な使用状態と、後端部を機体後方に開放する開放状態と、に切換可能な排藁処理装置１２と、排藁処理装置１２を使用状態に位置保持可能なロック機構４０と、が備えられ、ロック機構４０に、脱穀装置９に設けられた第一係合部４１と、排藁処理装置１２に設けられ、第一係合部４１と係合可能な第二係合部４２と、が備えられ、第一係合部４１及び第二係合部４２を係合状態と非係合状態とに切換可能な操作具４４と、係合状態における操作具４４を位置保持可能な保持機構４５と、が備えられている。【選択図】図７
