To provide a drying device that can improve drying efficiency of particulates and reducing costs.

The particulates to be dried are stored in a drying hopper 4, and an air supply pipe 7 and an exhaust line 9 are connected to the drying hopper 4. A heater 8 is interposed in a halfway part of the air supply line 7. Further, a compressed air supply line 12 branches off and is connected to the air supply line 7 upstream from the heater 8 in a circulation direction of air. Dehumidifiers 16, 17 are interposed in halfway parts of the compressed air supply line 12. The drying device includes a blower 2 for sending air into the air supply line 7 and a compressor 3 for compressing and sending the air into the compressed air supply line 12.