PURPOSE: To simplify a work to assemble a shield member and to improve durability by a method wherein a seal member which intercouples the opening of a case body and the opening of an outer drum in an airtight state is provided between the two openings in a state that the member is secured to the opening edge of the one opening and is brought into close contact with the peripheral edge of the opening of the other.

CONSTITUTION: A shield member 18 is formed in an annular manner by a flexible material, and is secured at a mounting part 18a of the upper peripheral edge thereof to the outer peripheral edge of an opening 3 of a case body 1. A lower peripheral edge 18b is arranged so that it can contact and separate from an outer drum cover 16 and is slidable over the upper surface of a cover 16. Meanwhile, an outer drum 15 is varied and arranged in positions A, B, and C according to whether water and a heavy substance, e.g. laundry, are contained through the working of cushioning and support device 10. Namely, right after containing of laundry and after a dry motion, the outer drum is arranged in the dry position A, the lower peripheral edge 18b of the shield member 18 and the upper surface of an outer drum cover 16 are brought into close contact with each other. After a motion to dehydrate laundry, the outer drum is arranged in the dehydration position B, and the lower peripheral edge 18b of the shield member 18 and the upper surface of the outer drum cover 16 are brought into close contact with each other.