Processing method and processing system

A processing system configured to process a combined substrate in which a first substrate and a second substrate are bonded to each other, the processing system comprising:

• an internal modifying apparatus configured to form a peripheral modification layer along a boundary between a peripheral portion of the first substrate as a removal target and a central portion of the first substrate;
• an interface modifying apparatus configured to form a non-bonding region in which bonding strength between the first substrate and the second substrate at the peripheral portion is reduced;
• a reference forming apparatus configured to form a reference modification layer, which serves as a determination reference of a formation position of either the peripheral modification layer or the non-bonding region, at a non-bonding surface of the first substrate not bonded to the second substrate;
• a periphery removing apparatus configured to remove the peripheral portion starting from the peripheral modification layer;
• and
• a control device and a program storage including a program.