An automatic chest compression device includes: a pressure member that makes abutting contact with the chest of a body a driving unit that makes the pressure member move to and fro a pressure receiving unit that allows rescuers hands to receive a reaction force which is generated on the side of the driving unit when the chest of the body is compressed by the pressure member and a control unit that calculates a substantial amount of depression of the chest by the pressure member, and controls a stroke of the pressure member given by the driving unit. As a result, chest compression can be applied reliably while any complicate operation is not required.