Silica glass jig for semiconductor industry and method of manufacturing the same

To provide a silica glass jig for the semiconductor industry not contaminating a semiconductor element and scarcely suffering from generating cracks, and to provide a method of manufacturing it. This silica glass jig for the semiconductor industry has many dimple-like depressions of 20 to 300 mum in width on the surface, trenches of 0.5 to 50 mum in width at a pitch of 20 to 300 mum and small projections of 1 to 50 mum in width and 0.1 to 10 mum in height distributed uniformly between these trenches and inside the trenches.