PURPOSE: To effect automatically and continuously drying operation, by providing an auxiliary electrode conveying part conveying an auxiliary electrode recovered by an auxiliary electrode recovery part to an auxiliary electrode feed holder of an auxiliary electrode feed part.

CONSTITUTION: A honeycomb structural body 1 arranged through a pad 2 is positioned at a position of an auxiliary electrode feed part 12 by conveying the honeycomb structural body 1 on a conveying path 16 and an auxiliary electrode 4 comprised of a perforated panel is put on the honeycomb structural body 1. Then a dielectric drying furnace 13 is passed through slowly by driving the conveying path 16 and drying of the honeycomb structural body 1 is enforced. Then positioned at an auxiliary electrode recovery part 14, the auxiliary electrode 4 is recovered from the upper part of the honeycomb structural body 1 obtained after drying and the auxiliary electrode 4 is conveyed up to a position of a lifter 15-3 on a downstream side by driving a return conveyor 15-2. Then the title device is constituted so that drying operation of the honeycomb structural body can be performed in succession by reusing the auxiliary electrode 4 by feeding the same within the auxiliary electrode feeding holder.