To prevent, in a foam material composed of a foam body having a fine cell structure, the drops of airtightness and dust proofing, which is caused by the effect of the gap, by making small the gap of a structure with height difference.

The foam material is composed of a foam body having a fine cell structure and has at least a long and narrow tape-like part. It is provided with a slit for it to be fitted to a height-different structure that is diagonally formed in the range of angle of 15-75 to the longitudinal direction of the part. The foam material preferably has a closed-cell structure or a semi-open, semi-closed cell structure as the fine cell structure. The one surface or both surfaces of the foam body can have an adhesive layer.