In a spectroscopy module 1, a light passing hole 50 through which a light L1 advancing to a spectroscopic portion 4 passes is formed in a light detecting element 5. Therefore, it is possible to prevent the relative positional relationship between the light passing hole 50 and a light detecting portion 5a of the light detecting element 5 from deviating. Moreover, the light detecting element 5 is bonded to a front plane 2a of a substrate 2 with an optical resin adhesive 63. Thus, it is possible to reduce a stress generated onto the light detecting element 5 due to a thermal expansion difference between the light detecting element 5 and the substrate 2. Additionally, on the light detecting element 5, a first pool portion 101 is formed so as to be located at least between the light detecting portion 5a and the light passing hole 50 when viewed from a direction substantially perpendicular to the front plane 2a. Thus, when the light detecting element 5 is attached to the substrate 2 via the optical resin adhesive 63, the optical resin adhesive 63 is pooled to remain at the first pool portion 101. Thus, the optical resin adhesive 63 is prevented from penetrating into the light passing hole 50.