A composite stretch member (10) has a plurality of fixing parts (14) for fixing an elastic member (13) and two sheet materials (11, 12), the fixing parts (14) being provided intermittently along a direction in which the elastic member (13) extends. The composite stretch member (10) has non-fixed parts (16) in which the elastic member (13) is not fixed to the two sheet materials (11, 12) between fixing parts (14) adjacent to each other along the direction in which the elastic member (13) extends. The composite stretch member (10) has folds (15) extending in the direction orthogonal to the direction in which the elastic member (13) extends. In a state in which the composite stretch member (10) is elongated 25% from the relaxed state thereof, the difference between the elongation rate of the composite stretch member and the elongation rate of the fixed parts, and the difference between the elongation rate of the composite stretch member and the elongation rate of the non-fixed parts are each within ±15%.L'invention concerne un élément étirable composite (10) comportant une pluralité de parties de fixation (14) permettant de fixer un élément élastique (13) et deux matériaux en feuille (11, 12), les parties de fixation (14) étant disposées de façon intermittente le long d'une direction dans laquelle s'étend l'élément élastique (13). L'élément étirable composite (10) comprend des parties non fixes (16) dans lesquelles l'élément élastique (13) n'est pas fixé aux deux matériaux en feuille (11, 12) entre des parties de fixation (14) adjacentes l'une à l'autre le long de la direction dans laquelle s'étend l'élément élastique (13). L'élément étirable composite (10) comporte des plis (15) s'étendant dans la direction orthogonale à la direction dans laquelle s'étend l'élément élastique (13). Dans un état dans lequel l'élément étirable composite (10) est allongé de 25 % par rapport à son état relâché, la différence entre le taux d'allongement de l'élément étirable composite et le
