PURPOSE: To easily and accurately measure the size of substrate after baking by printing patterns with a predetermined interval at a part of the surface of unbaked substrate and then baking.

CONSTITUTION: A pattern 5' having a constant interval is printed by a tungsten paste, for instance, to the edge of unbaked substrate 11'. A baked substrate 11 where the tungsten pattern 5 is sintered is formed by baking such unbaked substrate 11'. This baked substate 11 is contracted from unbaked sbstrate 11. Since the pattern 5 is formed in the same line having a constant interval, fluctuation in size of integrated circuit substrate 21 can be easily one accurately detected by comparing this pattern 5 with a scale showing clear interval by placing it on the pattern. Accordingly, the integrated circuit substrate 21 can be easily sorted for each size specification.