FIGS. 4A and 4B are a graph and table, respectively, showing the evaluation result of moisture contents according to APIMS-TDS of the Si surface (non-annealed) of the second substrate 20 after the activating process and the second substrate 20 (annealed) which has been annealed at 175??? C. for 30 sec on the stage of a bonding device (a device which bonds the first and second substrates 10 and 20)