To provide a livestock dung drying device capable of enhancing drying efficiency by shortening a processing time required for drying the livestock dung.

The undried livestock dung B of high moisture content fed into a drying drum 51 of the livestock dung drying device 50 is transferred from a starting end side toward a terminal end side while stirring it by rotation force of the drying drum 51 and a plurality of vanes 51e. The moisture contained in the undried livestock dung B is adsorbed/separated and dried by a drying hot air D fed into the drying drum 51. The small dried livestock dung A dried to a predetermined moisture content is released from a plurality of hole parts 51g of the vanes 51e to drop off it and make it flow down on a lower part inner peripheral surface of the drying drum 51. The large dried livestock dung A inhibited for passing through a plurality of the hole parts 51g and the undried livestock dung B are stirred by a plurality of vanes 51e and the drying hot air D is aggressively blown to the undried livestock dung B of high moisture content to dry/treat it to a predetermined moisture content.