Provided is a fluorescent signal detection apparatus including a reaction unit including a kit loading part in which a diagnostic kit is inserted to one area, a light source unit including a light source and a first barrel configured to surround the light source, a light receiving unit provided at one side of the light source unit and including a detection part and a second barrel configured to surround the detection part, and a case configured to surround the reaction unit, the light source unit, and the light receiving unit. Here, the diagnostic kit includes measuring parts and microstructures configured to accommodate a target to be measured, which is labeled by a fluorescent dye, and the microstructures are provided on the measuring parts.