Light detection device

A light detection device, comprising:

• a wiring substrate;
• a light receiving element mounted on the wiring substrate;
• a connection member electrically connecting the wiring substrate and the light receiving element;
• and
• a film-shaped adhesive member bonding the wiring substrate and the light receiving element, wherein
• a mounting region where the wiring substrate and the light receiving element overlap when viewed from a first direction in which the wiring substrate and the light receiving element are arranged has a pair of first sides facing each other in a second direction perpendicular to the first direction and a pair of second sides facing each other in a third direction perpendicular to the first direction and the second direction,
• the film-shaped adhesive member is disposed in the mounting region when viewed from the first direction, and
• the film-shaped adhesive member includes:
• a main body portion having a pair of first edges extending so as to notch the mounting region on a center side of the mounting region in each of the pair of first sides and a pair of second edges extending so as to notch the mounting region on the center side of the mounting region in each of the pair of second sides;
• and
• at least one projecting portion extending from at least one edge of each of the pair of first edges and at least one edge of each of the pair of second edges to a side opposite to a center of the mounting region.