PROBLEM TO BE SOLVED: To provide a foaming agent package which is excellent in resistance to chemicals and water tightness, and which securely floats on a water surface while a housing object is housed therein.SOLUTION: The foaming agent package includes: a package material which is foamed and dissolved when it is put in water； and an inner package which is packed inside the package material and which encloses the housing object. A specific gravity of the inner package in which the housing object is enclosed is smaller than that of water. In this structure, the plurality of inner packages may be packed in the package material, and a buffer material may be interposed between the inner package and the housing object.
