A cell-sheet releasing agent of the present invention contains an aminated polyrotaxane. The polyrotaxane constituting the skeleton of the cell-releasing agent of the present invention has a structure in which cavities of a plurality of cyclic molecules are threaded onto a linear molecule and both terminals of the linear molecule have a bulky cap bonded thereto so that the cyclic molecules are not dethreaded from the linear molecule. Furthermore, the aminated polyrotaxane contained in the cell-releasing agent of the present invention is a compound in which at least some of hydroxy groups in the cyclodextrin structure contained in the polyrotaxane are each substituted with a substituent having an amino group. According to this cell-sheet releasing agent, cultured cells anchored to the surface of a container can be released without damaging the cells and without controlling the temperature.