To provide a machine tool that prevents interference between a closing cover and a partition cover of a pallet replacing device without any design constraints, while reducing cost and space.

In this machining center 1, in a center shaft 17 of the pallet replacing device 2, a second center shaft 18 is provided which has a cam follower 20 engaging with the closing cover 24 at the upper end projecting from the center shaft 17. The second shaft is moved up and down only with vertical movement of the center shaft 17 to move the closing cover 24 between a closed position and an open position in association with the vertical movement of the center shaft 17.