To provide a bag opening tool capable of keeping a bag in an opened state at an arbitrary height of an inner face of a bucket of the arbitrary shape, and preventing the bag from being extruded to the external of the bucket, and the garbage from entering into a gap between the bag and the bucket, for taking out the garbage in the bag to throw away.

One end of an elastic band member 1 is joined to a windowed clip 2, the band member 1 is deflected, so that the other end of the band member 1 is passed through a window of the windowed clip 2 to form the ring shape where front and rear faces of the band member 1 are overlapped, the other end of the band member 1 is joined to a clip 3, and the clip 3 is fastened to the band member 1 to be stopped.