The present invention relates to a seedling transplanting machine. The task is increasing the operability and operation efficiency of seedling supplying in the seedling transplanting machine. The seedling transplanting machine according to the invention is characterized in that a seedling transplanting part (4) is provided at the back part of driving vehicle body (2). The left side part and the right side part of driving vehicle body are respectively provided with a carrying seedling preparing part (72) which supplies a seedling box or seedling fetching plate for carrying seedling from the front end of vehicle body. Each carrying seedling preparing part is formed by the external frames at left side and right side and a connector for connecting the external frame at left side and right side. The external frames at left side and right side are respectively installed with a rotating trolley (95) which supports the bases of left side part and right side part of seedling box or the bases of left side part and right side part of seedling fetching plate for carrying seedling. A space part (S) is provided between the left external frame and the right external frame. The front parts of left carrying seedling preparing part and right carrying seedling preparing part are configured more projected frontwards compared with the front end of running vehicle body. Furthermore the left-and-right space (L1) between the front parts of left carrying seedling preparing part and right carrying seedling preparing part which are configured in left-and-right direction in overhead view is smaller than the left-and-right space (L2) between the back parts of the left carrying seedling preparing part and right carrying seedling preparing part.
