PROBLEM TO BE SOLVED: To provide a seedling transplanting machine in which a front wheel and a rear wheel are made compatible, and the productivity is high.SOLUTION: A seedling transplanting machine is mounted with right and left traveling transmission cases 13 for transmitting the driving force to right and left running wheels, respectively, in a traveling vehicle body, and is provided with a seedling planting unit in the traveling vehicle body, and also is detachably provided with an auxiliary operation unit containing a fertilizing unit for supplying fertilizers in fields and a leveling unit for leveling the fields. The seedling transplanting machine is configured as follows: an auxiliary transmission case for transmitting the driving force to the auxiliary operation unit is mounted to the right and left traveling transmission cases detachably and in a mounting posture changeable manner, respectively; the mounting posture of the right and left auxiliary transmission cases is different when transmitting to
