Disclosed herein is a method of manufacturing two kinds of rectangular unit pieces having different optical properties from a base material sheet through cutting using a cutting frame including a cutter, the method including preparing a base material sheet having a large length to width ratio, the base material sheet exhibiting optical directivity in a longitudinal direction or in a lateral direction, preparing a cutting frame including at least on first cutter for cutting a first unit piece exhibiting optical directivity parallel to that of the base material sheet and at least one second cutter for cutting a second unit piece exhibiting optical directivity perpendicular to that of the base material sheet, the first cutter and the second cutter being arranged adjacent to each other in the lateral direction of the base material sheet, and sequentially cutting the base material sheet using the cutting frame in the longitudinal direction of the base material sheet to simultaneously manufacture the first unit piece and the second unit piece.