PROBLEM TO BE SOLVED: To provide a simple riding device enabling appropriate standing ride of a worker when the worker is tired with walking without deteriorating the steering operation of a riding seedling transplanter. SOLUTION: In the riding seedling transplanter having a steering handle 9 projecting toward the rear direction of a machine body, the riding device is configured to hold a narrow riding float 58 positioned at the transverse center of the rear part of the machine body and between planting rows of the transplanting device 10 and on which the worker can ride while standing, so that the riding float is held between a state of being towed by the machine body with a traction rod 57 and a state of being hung down from the machine body. COPYRIGHT: (C)2011,JPO&INPIT