A ring spacer interposed between plate-shaped objects above and below in a container for storing and transporting the plate-shaped objects when a plurality of plate-shaped objects is stored in an up-and-down direction includes a ring-shaped abutment portion and a control portion. An upper face and a lower face in the abutment portion have an approximately flat shape and the upper face in the abutment portion abuts against a lower face of a peripheral edge portion of the plate-shaped object. The lower face in the abutment portion abuts against an upper face of the peripheral edge portion of the plate-shaped object. The control portion includes a control portion upper face positioned to protrude further upward than the support face of the abutment portion and a control portion lower face positioned at an appropriate location in a thickness direction of the abutment portion.