A method is provided to arrange multiple food slices (m) in such a way that at least a portion of them overlap each other to form an
assembly (M) of food slices (m). In this method, the number of food slices (m) forming each
assembly (M) and the spacing (K) between the food slices (m) are automatically changed to control the weight of each
assembly (M) within a predetermined allowable range, and the total length of each assembly (M) is formed to a set length (A). Furthermore, the number of food slices (m) forming each assembly (M) and the spacing (K) between the food slices (m) are automatically changed according to the length (A) in the arrangement direction of the food slices (m).