A cell transplantation device for placing a cell group at a target region in at least one of an intradermal layer and a subcutaneous layer in a living body, including a device body including a protruding portion having an accommodating portion for accommodating a liquid composition including the cell group. The protruding portion has an opening that communicates with the accommodating portion, and the protruding portion penetrates a skin surface of the living body such that the opening of the protruding portion reaches the at least one of the intradermal layer and the subcutaneous layer and that the cell group accommodated in the accommodating portion is placed at the target region through the opening.
