To solve a problem wherein a conventional tool holder for display purpose is easily separated into a tool and a tool holder, which is apt to trigger shoplifting and mischief and to solve a problem wherein, even if having a pull-out prevention mechanism, another device is required for a separation.

This tool holder comprises a grip piece having a projecting part in its lower end, and a receiving cylinder having a locking means being spread by inserting the projecting part and holding the insertion state. After a spreading part of the receiving cylinder is inserted in a square hole of the tool, the projecting part is inserted in the receiving cylinder, so that the spreading part is spread to press-contact with the wall surface of the square hole, and the tool is held with holding the state.