Patent ID: 8462348

Claim:
A tunable interference filter comprising: a first substrate having light transmissivity; a second substrate opposed and bonded to one surface side of the first substrate; a first reflection film provided on the one surface of the first substrate; a second reflection film provided on a first surface of the second substrate facing the first substrate and opposed to the first reflection film via a gap; and a variable part that varies the gap, wherein the second substrate includes a light transmission hole formed in a position facing the first reflection film along a substrate thickness direction and penetrated from the first surface of the second substrate to a second surface opposite thereto, and a light transmissive member provided within the light transmission hole, the light transmission hole is formed in a tapered shape having a diameter dimension of an inner circumferential surface increasing from the first surface toward the second surface, and the light transmissive member has a light incident surface in parallel to the first reflection surface and the second reflection surface, a light exiting surface in parallel to the first reflection surface and the second reflection surface, and a tapered side surface having a diameter dimension increasing from the first surface toward the second surface, and the tapered side surface is in contact with the inner circumferential surface of the light transmission hole.