PROBLEM TO BE SOLVED: To provide a harvest pre-treatment device for use in a harvester in which the occurrence of a tension difference in an endless turning body between adjacent harvested material locking transport devices can easily be avoided and suppressed.SOLUTION: A harvest pre-treatment device is provided with tension regulation means 80 for imparting tension to an endless turning body 55 of a pair of harvested material locking transport devices 45, 45 adjacent in the horizontal direction of a machine body while return routes 59 of the endless turning body 55 are opposed to each other. The harvest pre-treatment device includes: a balance support 81 rotatably connected with one starting-edge side rotating wheel 52 for supporting a transport starting-edge side of an endless turning body 55 in one hand of the pair of harvested material locking transport devices 45, 45 and other starting-edge side rotating wheel 52 for supporting the transport starting-edge side of the endless turning body 55 in the other hand and a frame side support 84 supported to the frame side of the pair of harvested material locking transport devices 45, 45 while the balance support 81 is connected swingably.SELECTED DRAWING: Figure 6
