Abstract: The present invention provides a tool holder which realizes an improved applicability to tools with different diameters and attains high sealability and is capable of efficiently supplying a fluid at a predetermined position even when a fluid of high pressure is supplied. The tool holder comprises: an engaging member 4 provided on the top end side of a tool holding portion of a holder body 2 and comprising an inclined face 15 constructed in a manner such that the inside diameter becomes smaller toward the top end of the tool 10 held by the holder body 2; and an elastic member 5 as a stopper provided between the inclined face 15 and the outside periphery of the tool 10.