A wafer grinding device comprising: a chuck table configured to load a wafer thereon, to suction the wafer thereon, and to enable the suctioned wafer to be rotated in a predetermined speed; a spindle spaced from and above the chuck table at a predetermined distance, wherein the spindle is configured to descend and grind the suctioned wafer on the chuck table, wherein the spindle comprises: a driver unit configured to enable a grinding wheel to be rotated at a predetermined speed and be descend by a predetermined distance to contact the wafer; and a grinding wheel disposed coupled to the driver unit to grind the wafer by a predetermined thickness, wherein the grinding wheel includes a grinding body, and grinding teeth arranged along and on a bottom outer periphery of the grinding body, wherein the grinding teeth are segmented; and a cooling unit at least partially extending along a region between a departure point of the grinding teeth from the wafer during rotation of the teeth, and a re-encounter point of the teeth with the wafer during rotation of the teeth, wherein the region extends along a rotation path of the grinding teeth, wherein the cooling unit includes: a body formed in a circular arc shape having a center of the grinding wheel as a center thereof and having a curvature substantially equal to a curvature of the grinding wheel; and a groove formed in the body to allow the grinding teeth to pass therethrough, and wherein an inner bottom face of the body has a plurality of first dispensing holes formed therein, wherein the first dispensing holes are configured to dispense the cooling liquid or gas to outer bottom faces of the grinding teeth, wherein an inner side face of the body has a plurality of second dispensing holes formed therein, wherein the second dispensing holes are configured to dispense the cooling liquid or gas to outer side faces of the grinding teeth. a chuck table configured to load a wafer thereon, to suction the wafer thereon, and to enable the suctioned wafer to be rotated in a predetermined speed; a spindle spaced from and above the chuck table at a predetermined distance, wherein the spindle is configured to descend and grind the suctioned wafer on the chuck table, wherein the spindle comprises: a driver unit configured to enable a grinding wheel to be rotated at a predetermined speed and be descend by a predetermined distance to contact the wafer; and a grinding wheel disposed coupled to the driver unit to grind the wafer by a predetermined thickness, wherein the grinding wheel includes a grinding body, and grinding teeth arranged along and on a bottom outer periphery of the grinding body, wherein the grinding teeth are segmented; and a driver unit configured to enable a grinding wheel to be rotated at a predetermined speed and be descend by a predetermined distance to contact the wafer; and a grinding wheel disposed coupled to the driver unit to grind the wafer by a predetermined thickness, wherein the grinding wheel includes a grinding body, and grinding teeth arranged along and on a bottom outer periphery of the grinding body, wherein the grinding teeth are segmented; and a cooling unit at least partially extending along a region between a departure point of the grinding teeth from the wafer during rotation of the teeth, and a re-encounter point of the teeth with the wafer during rotation of the teeth, wherein the region extends along a rotation path of the grinding teeth, wherein the cooling unit includes: a body formed in a circular arc shape having a center of the grinding wheel as a center thereof and having a curvature substantially equal to a curvature of the grinding wheel; and a groove formed in the body to allow the grinding teeth to pass therethrough, and wherein an inner bottom face of the body has a plurality of first dispensing holes formed therein, wherein the first dispensing holes are configured to dispense the cooling liquid or gas to outer bottom faces of the grinding teeth, wherein an inner side face of the body has a plurality of second dispensing holes formed therein, wherein the second dispensing holes are configured to dispense the cooling liquid or gas to outer side faces of the grinding teeth. a body formed in a circular arc shape having a center of the grinding wheel as a center thereof and having a curvature substantially equal to a curvature of the grinding wheel; and a groove formed in the body to allow the grinding teeth to pass therethrough, and wherein an inner bottom face of the body has a plurality of first dispensing holes formed therein, wherein the first dispensing holes are configured to dispense the cooling liquid or gas to outer bottom faces of the grinding teeth, wherein an inner side face of the body has a plurality of second dispensing holes formed therein, wherein the second dispensing holes are configured to dispense the cooling liquid or gas to outer side faces of the grinding teeth.