To provide a labor saving kinetic energy taking-in device which utilizes energy taken in for opening/closing a door which requires large amount of traversing load for operation when a child walks through the door, since a large sized mat is necessary which accepts a wheelchair for elderly and handicapped person with sufficient margin and the large sized mat becomes heavy and bulky due to a possibility of a plurality of users traversing over the mat.

A labor saving kinetic energy taking-in device is operable with small amount of traversing load by interlocking a mat 3 with a weight 201 via a wire rope 204 so that a self weight of the mat 3 is counteracted by a self weight of the weight 201 and a gravity load of the weight 201 is applied to a counter direction of a gravity load direction of the mat 3.