To provide a device and a method of drying a resin coating material applied to a plastic base material capable of forming a hardened film in a short time without thermally deforming the plastic base material when the thermosetting resin coating material is applied onto the plastic base material, and then dried and hardened.

An endless conveying means 34 for conveying the plastic base material 43 coated with the resin coating material, in a circulated heating atmosphere, and one or more near infrared ray heaters 38 including a near infrared ray lamp mounted at an upper part of the endless conveying means 34 are installed in a thermosetting furnace 32, and a space 33 in the thermosetting furnace 32 is partitioned into one or more drying zones of which temperatures are independently controlled. Whereby the thermosetting resin coating material is applied to the thermally deformable plastic base material 43, and then the resin coating material can be hardened by applying the near infrared ray to the plastic base material 43 coated with the resin coating material in the circulating heating atmosphere.