Being brittle material, glass material is usually fabricated using photolithography and etching process, which are time consuming as well as involve chemical hazards. Therefore, researches are being carried out for fabricating glass micro features by various micromachining processes like grinding, milling, and turning. However, one of the major problems existing in these micromachining processes is the tool wear. This becomes more severe in the case of micro-grinding than in conventional grinding since micro grinding wheel is more sensitive to tool wear. Hence, this paper deals with the wear behavior of Polycrystalline Diamond (PCD) micro tool during micro grinding of Bk7 glass. An on-machine fabricated PCD tool of 670 μm diameter was used to micro-ground almost 65 slots keeping the same cutting conditions of feed rate 10μm/mint, depth of cut 5μm, and spindle speed 2000 rpm. It was found that tool wear caused the diameter reduction as well as length reduction. SEM image of the tool surface gave the clear indication of edge chipping and abrasion type of tool wear where grain pull out, microcracks and built up edge mechanism are responsible for these wear mode.