A top opening-closing mechanism for opening and closing a top of a container including a container body and the top includes a rolling element rotatably provided at the top and positioned on the outside of the container body in a planar view, a rail, a jack for lifting the rail, and a top resting table disposed adjacent to the container and mounting the top thereon. When the top is opened, the jack lifts the rail, the rail lifts the rolling element from below, and thereby the top is lifted up from the container body. Then, the rolling element rolls on the rail and the top resting table to move the top from above the container body to the top resting table.