PURPOSE:To grasp firmly seedling boxes and transfer them to a predetermined location by providing maintaining devices which separate accumulated seedling boxes and correct the inclination of the upper and lower directions and maintain them once to a predetermined transfer posture. CONSTITUTION:When the piston rods (a) of front and rear maintaining devices 26 protrude simultaneously, the maintaining protrusions and auxiliary plates 33a of maintaining plates 33 push up the convex portions 99a of a seedling box, and right and left seedling boxes 99 are lifted up to a predetermined height in a state of being horizontally maintained. Also, the plane portions and project ing portions of posture regulation plates 35 regulate the front, rear, right and left of seedling boxes located on the lower side than there, so it is convenient for the maintaining devices 26 to maintain seedling boxes next time. When seedling boxes are lifted up by means of maintaining devices, the moving frame 37 of a chuck device descends and at the same time, chucks 36 turn downward and grasp the uppermost seedling box by means of the lower surface of a lower frame 37a and the claws 36a of both chucks. The moving frame 37 which has grasped the seedling box is transferred to the starting end portion of a carrying device by rising and moving.
