To provide a sealing device for a hollow material which can suppress a use of an adhesive as small as possible, which can obtain a sufficient sealing effect to maintain the performance of a speaker and which can simultaneously and easily improve productivity.

The sealing device for the hollow material comprises: a sealing member 12 which can be inserted into an opening 2 of a cabinet 1 partly made of the hollow material, and which has a recess 14 formed in a direction crossing with the inserting direction of the cabinet 1 into the opening 2; and a sealing tape 13 adhered to the recess 14 of the member 12 to seal a gap between the opening 2 and the member 12 by inserting into the opening 2 of the cabinet 1.