PURPOSE: To reduce the size over the entire part of the device and to improve the efficiency of heating with hot air by providing a circulating wind path for circulating the hot air with a semiconductor heater for heating the wind from a blower, dust removing filters and a wind directing plate.

CONSTITUTION: An outside tank cover 40 has the wind path 54 for circulating the hot air at the time of drying. A first unit 56 connecting to the wind path 54 is connected to a first vertical side part 60 and a second unit 58 and includes an approximately U-shaped housing 64 having a second vertical side part 62 having the lateral direction length sufficiently long with the longitudinal length. The blower is provided within the first vertical side part 60. Grooves 72, 74 for guiding and supporting the moving type filter 22 and stationary type filter 68 inserted from an aperture 70 are formed on the right and left inner flanks of the second vertical side part 62. A groove 78 supporting the semiconductor heater 76 is formed below the groove 74. Further, the wind directing plate 80 for uniformly supplying the wind from the blower to the heater 76 is formed on the upper inside surface (top surface) of the second vertical side part 62.