PROBLEM TO BE SOLVED: To provide a rice transplanter capable of always detecting an accurate surface hardness without influence of uneven state on the surface of a field by arranging a hardness sensor for detecting the surface hardness of a field by a specific method. SOLUTION: This rice transplanter is equipped with a hardness sensor 127 for detecting the surface hardness of a field. The hardness sensor 127 is installed so as to drop a falling body 128 from above on a field and to detect the hardness from the sinkage. In the operation, preferably the falling body 128 is vertically movably supported on parallel link mechanisms 131 and 132 and preferably a sensor unit mechanism 149 having the hardness sensor 127 is linked and connected to a planting depth changing mechanism.
