To provide a chuck table mechanism having a function for cooling a chuck table.

This chuck table mechanism 5 includes a chuck table 6, and a cooling medium supply means 7. The chuck table 6 includes a holding table 61, and a support member 62. The support member 62 is provided with a first communication path 633 communicating with one end of a cooling medium flow path 622 for flowing a cooling medium, and a second communication path 634 communicating with the other end. The cooling medium supply means 7 includes a cooling medium cooling means 71, a pump 72 for supplying the cooling medium, a cooling medium supply pipe 73, a cooling medium return pipe 74, and a switching valve 75 which can be switched between a first mode in which the cooling medium supply pipe 73 communicates with the first communication path 633 and the second communication path 634 communicates with the cooling medium return pipe 74, and a second mode in which the cooling medium supply pipe 73 communicates with the second communication path 634 and the first communication path 633 communicates with the cooling medium return pipe 74.