The invention relates to a vacuum drying device. Said device has a sealed housing (3) into which bulk material or a liquid can be fed, via an input opening (1). The dried material or the residual distillation liquid is able to leave the housing via an output opening (2). The interior of the housing (30) is connected to the suction side of a vacuum pump (12). Several heating plates (4) are also located in the housing interior, the material being moved through between said heating plates (4). The inventive device is characterised in that the heating plates (4) are configured with heating-medium channels (41) with inlets (41') and outlets (41'') and in that an auxiliary pump or auxiliary fan (14) is provided. The suction side of said auxiliary pump or auxiliary fan (14) is connected to a material- or liquid-free area of the housing interior (30) and its pressure side is connected to the inlets (41') of the heating-medium channels (41). In addition, the outlets (41'') are connected to the suction side of the vacuum pump (12) and a conveying device is provided for moving the material through between the heating plates (4). Separate conveying means (5) located between the heating plates (4) and/or the heating plates themselves can be moved by means of said conveying device in such a way that they oscillate.