To make it possible to suck and remove dust and dirt which are dispersingly floating around the surrounding area of a loading port by using a suction air of an exhauster by providing a cylinder-shaped body, which is provided with a hole clearance for dust suction on its cylinder wall, on an upper area inside the loading port so that it may extend in the front and rear and communicating its bore with the suction opening of an exhauster directly.

A drying part (b) inside equipment body 1 is shaped up in such a fashion that a hot air passage 11 may be located outside in the equipment body 1 while an exhaust air passage may be located inside in the equipment body 1. A loading port (w), which is communicated with the air conducting passage 11, is provided on an equipment wall 1c on the side surface of the equipment body 1 and the loading port (w) is closed with a loading hopper 17 which is freely openable. A hollow cylinder-shaped body 8, which opens a hole clearance 80 on its peripheral wall is formed in a site close to the upper part inside the hot air conducting passage 11 laid out the outside site on both sides in the equipment body 1 in such a fashion that it may extend in the front and rear directions and loaded, thereby communicating the ear end of the cylinder-shaped body 8 with the suction opening 40 of an exhauster 4 loaded on the rear side of the equipment body 1 by way of an exhaust duct 6 which bypasses a grain flow-down passage 12 of the drying part (b) directly and controlling openly its communication with the shutter (S).