To enable a bag shape to be maintained so that waste can easily be put thereinto, and to prevent waste therein from clinging thereto upon separating a maintaining body from the bag.

A bag shape can be maintained so that waste can easily be put thereinto, by inserting a maintaining body into a bag 6 to allow the bag to be settle along the shape of the maintaining body. After storing waste, the maintaining body is pulled out of the bag, and subsequently the opening of the bag is closed. The maintaining body is constituted of a plurality of bars 1 extending straight in a perpendicular direction with the upper ends thereof or upper parts thereof linked by annular bodies 2, 3, and hence the maintaining body can smoothly be pulled out of the bag without a risk for a content, i.e., waste, to cling to the maintaining body when the maintaining body is pulled out of the bag. The opening of the bag can be held on the upper end of the maintaining body, by inwardly bending the edge of the opening of the bag and fixing the same thereonto with a fixing means 7 having a spring property.