A description one embodiment of the present invention will be described with reference to the accompanying drawings referring to fig1 the overall coating apparatus of the embodiment is shown the coating apparatus comprises a cylindrical bottomed coating tub 1 having an upper opening two support shafts 2 protrude from opposite sides of an outer circumferential wall of the coating tub 1 respectively two support boxes 3 a and 3 b are provided so as to respectively correspond to the support shafts 2 bearings not shown are provided in the support boxes 3 a and 3 b for rotatably supporting the support shafts 2 an electric motor not shown is provided in one of the support boxes 3 a and 3 b so that the coating tub 1 may be rotated a predetermined angle about the support shafts 2 as a result objects to be coated can easily be placed into the coating tub 1 and finished coated products can be taken out of the coating tub 1 after the completion of the coating a duct 4 has one of two ends located over the central interior of the coating tub 1 as shown in fig1 the other end of the duct 4 is connected to a heated air source not shown after the completion of the coating duct 4 supplies drying air to the products the coating tub 1.