To provide a clean house for assembling electric appliances at a local site by filling useless space in an internal space so that absorption of moisture by insulation materials and deterioration of dielectric strength can be prevented to promote enhancement of quality of an assembly work and also implement moisture and dust removal efficiently in a short time, thereby contributing to a reduction of cost as well as a shortened construction work of a local house for assembly.

Inside an assembly room 2 and a spare room 3 a freely shrinkable airbag device 6 is arranged. Meanwhile, in the upper direction of the assembly room 2 and the spare room 3, piping 7 is installed, in a one end of the piping 7 a gas generator is connected and to the other end the above airbag device 6 is detachably fixed. Furthermore, a vacuum pump 13 is installed in the piping 7.