To effectively prevent a clip from being disengaged due to impact such as drop.

The box comprises a box body 1, a lid 2 and a belt-like clip 5 for fastening then. In this case, the box is preferably a hard box wherein an upper face of the lid 2 with which the clip 5 is an contact has an ascending inclination of 3 to 20 degrees from an end toward the center, wherein a corner 8 from a side of the lid 2 toward an upper face is preferably such that the ratio of the radius of the corner 8 to the length of the upper face is 1/5 to 1/20.