A particle extraction apparatus (1; 3; 4) comprising: a first extraction unit comprising a first detection system for detecting a target particle from a whole sample flowing, and a first extraction system for extracting an extraction sample containing the target particle on the basis of information generated by a first processing system wherein said first processing system uses a detection result of the first detection system, wherein the first extraction system of the first extraction unit is configured to extract the extraction sample containing the target particle regardless of the presence of a non-target particle with a short passage time interval with the adjacent target particle; a second extraction unit comprising a second detection system for detecting the target particle from the extraction sample and a second extraction system for extracting the target particle on the basis of information generated by a second processing system wherein said second processing system uses a detection result of the second detection system, wherein the second extraction system of the second extraction unit is configured to extract, from the extraction sample as it flows, only the target particle, and not to extract the target particle if a non-target particle is present within said short passage time interval from the adjacent target particle, wherein a flow path exists between an outlet of the first extraction unit and an inlet of the second extraction unit; and a stirring unit disposed along the flow path between the first extraction unit and the second extraction unit, wherein the stirring unit is configured to change a particle interval in the extraction sample. a first extraction unit comprising a first detection system for detecting a target particle from a whole sample flowing, and a first extraction system for extracting an extraction sample containing the target particle on the basis of information generated by a first processing system wherein said first processing system uses a detection result of the first detection system, wherein the first extraction system of the first extraction unit is configured to extract the extraction sample containing the target particle regardless of the presence of a non-target particle with a short passage time interval with the adjacent target particle; a second extraction unit comprising a second detection system for detecting the target particle from the extraction sample and a second extraction system for extracting the target particle on the basis of information generated by a second processing system wherein said second processing system uses a detection result of the second detection system, wherein the second extraction system of the second extraction unit is configured to extract, from the extraction sample as it flows, only the target particle, and not to extract the target particle if a non-target particle is present within said short passage time interval from the adjacent target particle, wherein a flow path exists between an outlet of the first extraction unit and an inlet of the second extraction unit; and a stirring unit disposed along the flow path between the first extraction unit and the second extraction unit, wherein the stirring unit is configured to change a particle interval in the extraction sample.