Mems device manufacturing method and mems device

A MEMS device manufacturing method comprising:

• radiating laser light from a first surface side of a first substrate to form a modified region inside the first substrate along a dividing line that extends in a direction perpendicular to the first surface side;
• bonding a main surface of a second substrate to a main surface of the first substrate via a bonding portion that is formed along the dividing line, with the bonding portion constructed to block at least a portion of the laser light;
• and
• applying stress to the modified region of the first substrate to collectively divide the first substrate and the second substrate.

A MEMS device comprising:

• a first substrate having a device part disposed on a first main surface thereof;
• and
• a second substrate having a first main surface that is bonded to a second main surface of the first substrate via a bonding portion;
• wherein the bonding portion comprises a metal that is constructed to block laser light that has a wavelength that is configured to pass through the first substrate and the second substrate.