An elastic member according to an embodiment includes a first region and a second region, wherein a first direction defined as a width direction and a second direction defined as a longitudinal direction in the elastic member, the first region is defined as a folding region that is folded with the first direction as a folding axis, and the second region is defined as an unfolding region, a first pattern portion including a plurality of patterns is disposed in the first region, a length of the plurality of patterns in the first direction is greater than a width of the plurality of patterns in the second direction, the first region includes a first column, a second column, and a third column that extend in the first direction and are sequentially disposed in the second direction around the folding axis, the first region includes a plurality of pattern groups respectively disposed in the plurality of columns of the first region and including the plurality of patterns spaced apart from each other in the first direction, and a size of a pattern of the first column is different from a size of a pattern of the second column.