Interference filter having adhesive and warp reduction grooves

An interference filter comprising:

• a first substrate;
• a second substrate that faces one side of the first substrate and is bonded to the first substrate;
• a first reflection film formed on the one side of the first substrate that faces the second substrate;
• and
• a second reflection film provided on the second substrate and faces the first reflection film,
• the first substrate including
• a first gap formation region in which the first reflection film is disposed and which is not contact with the second substrate, and
• a first bonding region provided outside the first gap formation region and in contact with the second substrate,
• the second substrate including
• a second gap formation region in which the second reflection film is disposed and which faces the first gap formation region with a gap therebetween,
• a second bonding region provided outside the second gap formation region and in contact with the first bonding region of the first substrate,
• adhesive grooves which are formed in the second bonding region and into which an adhesive is applied, and
• warp reduction grooves formed between the adhesive grooves and the second gap formation region, and
• wherein the first substrate and the second substrate are adhesively bonded to each other with the adhesive applied into the adhesive grooves with the first bonding region and the second bonding region bonded to each other.