Abstract: Tool-holder B f6r gripping and changing tools for an industrial robot suitable for fixing to a rotary wrist-joint (5) of a robot arm, intended to carry one tool at a time. This tool-holder B comprises an upstream part C able to be fixed to the wrist-joint (5), a downstream part D able to be fixed to a tool (E1, . . . ) and remaining integral with the latter at each tool change, the two parts C and D being equipped with additional means for assembly and for rapid locking as well as unlocking and with detachable connectors (28, 32; 29, 37) for supplying the tool (E1) with fluid and electricity, the upstream part C containing a jack (7, 22) capable of displacing the locking and unlocking components (25, 41, 42, 14, 15, 16), and the downstream part D can be arranged in a tool magazine with the associated tool. The one-piece nature of the tool gripped in the tool-holder B ensures ease and speed of the robot's arm movements in space, maximum robot reliability, as well as rapid and powerful locking and unlocking.