Epidermal keratinocytes not having magnetic fine particles incorporated therein and epidermal keratinocytes having magnetic fine particles incorporated therein are seeded in a 24-well ultralow adhesion plate. A neodymium magnet is disposed outside the well bottoms, and the cells are cultured for one day. As a result, control epidermal keratinocytes not having magnetic fine particles incorporated therein do not adhere to the well bottoms, resulting in non-formation of undifferentiated cell sheet. By contrast, epidermal keratinocytes having magnetic fine particles incorporated therein, while being attracted to the well bottoms by magnetic force, form a multilayered cell sheet. This cell sheet can be easily recovered by removing the neodymium magnet disposed outside the well bottoms, causing a magnet having a hydrophilic film stuck thereto to come close to the cell sheet from upside and attract it through the hydrophilic film, and updrawing them.
