A
processing method for a
wafer (11) for
processing a
wafer (11), wherein a component (15) having several elevations (17) is formed in each of areas of a front surface of the
wafer (11) which is divided by several intersecting division lines (13) formed in an intersecting manner, wherein the
processing method for a wafer (11) comprises: a training step for a first
cut groove (23) to form first
cut grooves (23) each having a depth corresponding to a finished thickness of each of the component chips (27), by a first
cutting blade (14) having a first thickness, along the parting lines (13) of a front surface side (11a) of the wafer (11); a scanning step of the front surface of the wafer (11) with visible light using a scanning unit (18) in which an alignment mark is detected and the parting line (13) to be
cut is detected based on the alignment mark, prior to the training step for a first cut groove; a sealing step to seal the front surface of the wafer (11) including the first cut grooves (23) with a sealing material (20) after the training step for a first cut groove (23) has been carried out; a
grinding step to
grind the wafer from a rear surface side (11b) of the wafer (11) to the finished thickness of each of the device chips (27) to
expose the sealing material (20) in the first cut grooves (23) after the sealing step has been performed; an alignment step for picking up the front surface of the wafer (11) by the sealing material (20) by the
pickup medium (18) using
infrared light from the front surface (11a) of the wafer (11), detecting an alignment mark and detecting the parting line (13) to be cut based on the alignment mark after the
grinding step has been performed; and a division step for
cutting the sealing material (20) in the first cut grooves (23) by a second
cutting blade (14A) having a second thickness smaller than the first thickness of the first cutting blade (14), along the division lines (13) from the front surface (11a) of the wafer (11) and parts of the wafer (11) into individual device chips (27), each of which has its front surface and four side surfaces surrounded by the sealing material (20) after the alignment step has been performed, wherein in the sealing step the front surface of the wafer (11) is sealed with a sealing material (20) which has such a transmission property that
infrared rays which are to be absorbed by the
infrared light receiving means (18) pass through the sealing material (20).