PROBLEM TO BE SOLVED: To prevent deterioration of appearance of a non-stretchable region. SOLUTION: The front exterior body 12F and the rear exterior body 12B are separated in the front-rear direction, and the front exterior body 12F and the rear exterior body 12B are intermediate in the width direction in the front-rear direction range having the absorber 56. The non-stretchable region A1 provided in the stretchable region A1 and the stretchable regions A2 provided on both sides of the non-stretchable region A1 in the width direction, and the non-stretchable region A1 has an inner sheet layer 12H and an outer sheet continuous from the stretchable region A2. It has a layer 12S and an independent contraction portion 19 that is left between the inner sheet layer 12H and the outer sheet layer 12S and is continuous from the elastic member of the expansion / contraction region A2, and both in the width direction and the front-rear direction in the non-expansion / contraction region A1. It is solved by having a reinforcing joint portion 23 in which the inner sheet layer 12H and the outer sheet layer 12S are directly welded at at least one place including the central portion in the above. [Selection diagram] FIG. 9【課題】非伸縮領域の見栄えの悪化を防止する。【解決手段】上記課題は、前側外装体１２Ｆ及び後側外装体１２Ｂが前後方向に離間され、前側外装体１２Ｆ及び後側外装体１２Ｂは、吸収体５６を有する前後方向範囲に、幅方向中間に設けられた非伸縮領域Ａ１と、この非伸縮領域Ａ１の幅方向両側に設けられた伸縮領域Ａ２とを有し、非伸縮領域Ａ１は、伸縮領域Ａ２から連続する内側シート層１２Ｈ及び外側シート層１２Ｓと、これら内側シート層１２Ｈ及び外側シート層１２Ｓ間に残された、伸縮領域Ａ２の弾性部材から連続する独立収縮部分１９とを有し、非伸縮領域Ａ１おける幅方向及び前後方向の両方における中央部を含む少なくとも一か所に、内側シート層１２Ｈ及び外側シート層１２Ｓが直接に溶着された補強接合部２３を有している、ことにより解決される。【選択図】図９
