A wafer processing method divides a wafer along a plurality of crossing streets formed on the front side of the wafer to thereby partition a plurality of regions where a plurality of devices are respectively formed. The method includes a division groove forming step of cutting the back side of the wafer along each street by using a cutting blade to thereby form a division groove along each street with a predetermined thickness left between the bottom of the division groove and the front side of the wafer, a wafer supporting step of attaching the back side of the wafer to a dicing tape supported by an annular frame, and a wafer dividing step of applying an external force to the wafer attached to the dicing tape to thereby divide the wafer into the individual devices along the streets where the division grooves are respectively formed.