A sockliner includes: a base layer portion formed of a three-dimensional mesh structure body; and an upper layer portion formed of a sheet-like structure body that covers an upper surface of the base layer portion. The upper layer portion includes a through-hole group including a plurality of holes, and each of the holes is located inward from a peripheral edge of the upper layer portion without reaching the peripheral edge. In a case where a surrounding region is defined as a region between the peripheral edge and a position offset by 4.0 mm inward from the peripheral edge, the through-hole group includes an outermost hole group including a plurality of holes located closest to the peripheral edge so as to overlap with the surrounding region and to align along the peripheral edge.