A light detection device comprising: a Fabry-Perot interference filter that has a first mirror and a second mirror with variable distance therebetween and is provided with a light transmission region to transmit light according to a distance between the first mirror and the second mirror; a light detector that detects the light transmitted through the light transmission region; a support member (4, 4A, 4B) that has a placement surface on which a portion of a bottom surface of the Fabry-Perot interference filter outside the light transmission region in the bottom surface is placed; and an adhesive member that adheres the Fabry-Perot interference filter and the support member (4, 4A, 4B) to each other, wherein an elastic modulus of the adhesive member is smaller than an elastic modulus of the support member (4, 4A, 4B), at least a part of a lateral surface (102, 102a, 102b, 102c, 102d) of the Fabry-Perot interference filter is located at the placement surface such that a part of the placement surface extends beyond the lateral surface (102, 102a, 102b, 102c, 102d) to its outside, and the adhesive member is disposed in a corner portion (C1, C2, C3, C4, C5, C6) formed by the lateral surface (102, 102a, 102b, 102c, 102d) and the part of the placement surface that extends beyond the lateral surface (102, 102a, 102b, 102c, 102d) to its outside and contacts each of the lateral surface (102, 102a, 102b, 102c, 102d) and the part of the placement surface that extends beyond the lateral surface (102, 102a, 102b, 102c, 102d) to its outside so that the surface of the adhesive member extending from the placement surface to the lateral surface (102, 102a, 102b, 102c, 102d) of the Fabry-Perot interference filter is exposed to air. a Fabry-Perot interference filter that has a first mirror and a second mirror with variable distance therebetween and is provided with a light transmission region to transmit light according to a distance between the first mirror and the second mirror; a light detector that detects the light transmitted through the light transmission region; a support member (4, 4A, 4B) that has a placement surface on which a portion of a bottom surface of the Fabry-Perot interference filter outside the light transmission region in the bottom surface is placed; and an adhesive member that adheres the Fabry-Perot interference filter and the support member (4, 4A, 4B) to each other, wherein an elastic modulus of the adhesive member is smaller than an elastic modulus of the support member (4, 4A, 4B), at least a part of a lateral surface (102, 102a, 102b, 102c, 102d) of the Fabry-Perot interference filter is located at the placement surface such that a part of the placement surface extends beyond the lateral surface (102, 102a, 102b, 102c, 102d) to its outside, and the adhesive member is disposed in a corner portion (C1, C2, C3, C4, C5, C6) formed by the lateral surface (102, 102a, 102b, 102c, 102d) and the part of the placement surface that extends beyond the lateral surface (102, 102a, 102b, 102c, 102d) to its outside and contacts each of the lateral surface (102, 102a, 102b, 102c, 102d) and the part of the placement surface that extends beyond the lateral surface (102, 102a, 102b, 102c, 102d) to its outside so that the surface of the adhesive member extending from the placement surface to the lateral surface (102, 102a, 102b, 102c, 102d) of the Fabry-Perot interference filter is exposed to air.