A jig for assisting in aligning a plurality of rectangular workpieces is in the form of a plate having a plurality of grooves parallel to each other. The grooves have respective one ends aligned straight with each other and have a depth smaller than the thickness of the workpieces. After the workpieces have been fitted in the respective grooves, an adhesive tape is applied to the workpieces and the workpieces are transferred from the jig to the adhesive tape, so that the workpieces are arrayed in alignment with each other on the adhesive tape. The workpieces on the adhesive tape are prevented from being placed in different positions and orientations, and can subsequently be processed efficiently.