Indirect heating type drying apparatus

The invention provides an indirect heating type dryer which can realize volume reduction of a dried object with drying processing, the high filling rate of a dried object and the uniformity of a dried objected in a housing. The indirect heating type dryer indirectly heat the dried object in the housing for drying process by circulating a heating medium in a rotation shaft (4) and stirring wings (20), wherein the stirring wings (20) are of a wedge shape. Each stirring wing has a front side (S1) facing the housing, a first wing surface (20a) and a second wing surface (20b), wherein the first wing surface (20a) gradually inclines to the front side (S1) from a front end part (20c) of a front side of the rotation shaft (4) in a rotation direction (M) to a rear end part (20d) of a rear side toward the rotation direction (M).