Abstract: A sock liner designing apparatus, a sock liner designing method and a recording medium for a recording program are provided that are used to design sock liners that enable functions of footwear desired by a user to be attained when the user wears the footwear. A sock liner designing apparatus includes: an input circuitry that receives an input of measured foot data; a processor that calculates design data of a sock liner based on the foot data received through the input circuitry; and an output circuitry that outputs the design data calculated by the processor. The processor adjusts the design data based on a difference between received footwear functions and footwear data.

Abstract: 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.