A method for indirectly detecting a target particle dispersed and moving randomly in a solution using a luminescent probe, comprising: (a) a step for preparing a solution containing a target particle to be detected and one or more types of a luminescent probe that directly or indirectly binds to the target particle; (b) a step for forming a complex containing the target particle and the luminescent probe in the solution; (c) a step for removing luminescent probes not bound to the target particle from the solution containing the complex, thereby recovering the complex; (d) a step for dissociating the luminescent probe from the recovered complex and separating the free luminescent probe and the target particle, thereby separately recovering the free luminescent probe and the target particle; (e) a step for repeating one or more times a cycle consisting of the following steps: (a') a step for preparing a solution by newly adding the luminescent probe to the target particle recovered by separating from free luminescent probe in the step (d); (b') a step for forming a complex containing the target particle and the luminescent probe in the solution following the step (a'); (c') a step for separating luminescent probes not bound to the target particle, thereby recovering the complex from the solution following the step (b'); and, (d') a step for dissociating the luminescent probe from the complex recovered in the step (c') followed by mutually separating and recovering free luminescent probes and the target particle; followed by preparing a single measurement sample solution containing the total amount of free luminescent probes recovered in the step (d) and the step (d'); and, (f) a step for calculating the number of molecules of the luminescent probes in the measurement sample solution by a method consisting of detecting light emitted from the luminescent probe in a photodetection region of an optical system of a confocal microscope or multi-photon microscope while moving the location of the photodetection region in the measurement sample solution using the optical system. (a) a step for preparing a solution containing a target particle to be detected and one or more types of a luminescent probe that directly or indirectly binds to the target particle; (b) a step for forming a complex containing the target particle and the luminescent probe in the solution; (c) a step for removing luminescent probes not bound to the target particle from the solution containing the complex, thereby recovering the complex; (d) a step for dissociating the luminescent probe from the recovered complex and separating the free luminescent probe and the target particle, thereby separately recovering the free luminescent probe and the target particle; (e) a step for repeating one or more times a cycle consisting of the following steps: (a') a step for preparing a solution by newly adding the luminescent probe to the target particle recovered by separating from free luminescent probe in the step (d); (b') a step for forming a complex containing the target particle and the luminescent probe in the solution following the step (a'); (c') a step for separating luminescent probes not bound to the target particle, thereby recovering the complex from the solution following the step (b'); and, (d') a step for dissociating the luminescent probe from the complex recovered in the step (c') followed by mutually separating and recovering free luminescent probes and the target particle; followed by preparing a single measurement sample solution containing the total amount of free luminescent probes recovered in the step (d) and the step (d'); and, (a') a step for preparing a solution by newly adding the luminescent probe to the target particle recovered by separating from free luminescent probe in the step (d); (b') a step for forming a complex containing the target particle and the luminescent probe in the solution following the step (a'); (c') a step for separating luminescent probes not bound to the target particle, thereby recovering the complex from the solution following the step (b'); and, (d') a step for dissociating the luminescent probe from the complex recovered in the step (c') followed by mutually separating and recovering free luminescent probes and the target particle; followed by preparing a single measurement sample solution containing the total amount of free luminescent probes recovered in the step (d) and the step (d'); and, (f) a step for calculating the number of molecules of the luminescent probes in the measurement sample solution by a method consisting of detecting light emitted from the luminescent probe in a photodetection region of an optical system of a confocal microscope or multi-photon microscope while moving the location of the photodetection region in the measurement sample solution using the optical system.