PROBLEM TO BE SOLVED: To provide a stretchable sheet comprising air permeability because of presence of an open hole and in which no hole is formed on an outer layer.SOLUTION: The production method of the stretchable sheet comprises a supply step for interposing a flexible elastic film 30 between a first sheet layer 21 comprising no flexibility, and a second sheet layer 22 comprising no flexibility, in the supply step, thermofusion energy is applied to a region of plural joint parts which are arranged at intervals by a thermofusion device from outside of the first sheet layer 21 and the second sheet layer 22, for melting the elastic film 30, then the first and second sheet layers 21, 22 are jointed directly or jointed through the elastic film, at the plural joint parts. No hole is formed in whole region of the joint parts, the first and second sheet layers 21, 22 are left, and between the elastic film 30 and the joint part 40, on at least a boundary part thereof in a stretchable direction, an open hole 31 is provided.SELECTED DRAWING: Figure 8【課題】貫通孔の存在により通気性があり、しかも外層には孔が形成されない伸縮シートを得る。【解決手段】伸縮性を有しない第１シート層２１と、伸縮性を有しない第２シート層２２との間に、伸縮可能な弾性フィルム３０を伸長状態で介在させる供給工程と、この供給工程において、前記第１シート層２１及び前記第２シート層２２の外方から、熱溶融装置によって間隔を空けた多数の接合部領域に熱溶融エネルギーを与え、前記弾性フィルム３０を溶融し、前記第１シート層２１及び前記第２シート層２２を、直接又は弾性フィルムを介して多数の接合部で接合する。 前記接合部領域全体に孔が形成されておらず前記第１シート層２１及び前記第２シート層２２を残存させるとともに、前記弾性フィルム３０と前記接合部４０との、少なくとも前記伸長方向の境界部分に貫通孔３１を形成する【選択図】図８
