To provide a lid opening and closing tool capable of opening and closing a lid for a drinking water container quickly and smoothly and capable of rotating the lid easily.

The lid opening and closing tool is composed of a flat plate lid opening and closing tool body, a hole formed at the center of the tip of the lid opening and closing tool body in which the lid of the drinking water container can be inserted, a plurality of stoppers formed on the inside face of the hole which can be meshed with the periphery of the lid of the drinking water container inserted into the hole, a hole formed at the center of the back end in which a finger is inserted and a hanging string at the center of the body which is hung on the upper part of the drinking water container to prevent the body from falling down.