The present invention aims at providing a foaming tool capable of highly efficiently producing creamy foam containing ultra fine bubbles in high proportion. The foaming tool includes a double-layered cloth body composed of vertically overlapped cloth bodies obtained by plain weaving synthetic-resin-fiber warp and wept yarns so as to cause them to alternately position up and down with weave textures of ≦300 μm length and width. The double-layered cloth body has an air layer interposed between the vertically overlapped cloth bodies. The double-layered cloth body is folded once at an appropriate center in the longitudinal direction thereof and thus joined edge portions are assembled and are stitched together to thereby provide a tab portion of gather. In such a constitution, below the tab portion, a foaming auxiliary portion produced by assembling of a cloth body having the same quality as that of the cloth described above is provided.