Provided is an indirectly heating rotary dryer which has achieved enhanced energy-saving performance by reducing heating tubes non-contacting with material to be dried and reducing power required for rotation even when a hold up ratio is increased. Specifically provided is an indirectly heating rotary dryer having four partition walls 16 extended respectively along an shaft center C in an inner space of a rotating shell 10 at angle intervals of 90 degrees in the vertical and horizontal directions. The four partition walls 16 partition the inner space of the rotating shell 10 at a lateral section of the rotating shell 10 into four approximately-sector-shaped small spaces K respectively extended along the shaft center C. Heating tubes 11 are aligned in the rotating shell 10 in three lines extended respectively in parallel to the shaft center C of the rotating shell 10. The heat tubes 11 heat and dry the material H to be dried by supplying heated steam to the heating tubes 11 and performing heat exchange with the material H to be dried in the rotating shell 10.
