A particle imaging apparatus comprising: a flow path comprising a first flow path section, a second flow path section connected downstream of the first flow path section, and a third flow path section that is branched from the first flow path section, between the first flow path section and the second flow path section, the flow path configured to cause a measurement sample including particles to flow; a particle detection unit comprising a light source that applies light to a particle that flows in the first flow path section, and a light detector that receives light generated from the particle by application of the light; a particle sorting unit capable of adjusting a flow direction of the particle flowing in the first flow path section such that the flow direction is selected from among at least a direction toward the second flow path section and a direction toward the third flow path section, based on an intensity of the light received by the light detector; and a particle imaging unit configured to take an image of a particle that flows in the second flow path section, wherein the flow path is structured such that a cross-sectional area of the second flow path section is greater than a cross-sectional area of the first flow path section, wherein the first flow path section and the second flow path section are disposed so as to be linearly aligned, wherein the particle sorting unit is arranged such that the flow direction of an imaging target particle in the first flow path section is not changed to guide the imaging target particle into the second flow path section, and the flow direction of a particle other than the imaging target particle in the first flow path section is changed to the direction toward the third flow path section to guide the particle other than the imaging target particle into the third flow path section. a flow path comprising a first flow path section, a second flow path section connected downstream of the first flow path section, and a third flow path section that is branched from the first flow path section, between the first flow path section and the second flow path section, the flow path configured to cause a measurement sample including particles to flow; a particle detection unit comprising a light source that applies light to a particle that flows in the first flow path section, and a light detector that receives light generated from the particle by application of the light; a particle sorting unit capable of adjusting a flow direction of the particle flowing in the first flow path section such that the flow direction is selected from among at least a direction toward the second flow path section and a direction toward the third flow path section, based on an intensity of the light received by the light detector; and a particle imaging unit configured to take an image of a particle that flows in the second flow path section, wherein the flow path is structured such that a cross-sectional area of the second flow path section is greater than a cross-sectional area of the first flow path section, wherein the first flow path section and the second flow path section are disposed so as to be linearly aligned, wherein the particle sorting unit is arranged such that the flow direction of an imaging target particle in the first flow path section is not changed to guide the imaging target particle into the second flow path section, and the flow direction of a particle other than the imaging target particle in the first flow path section is changed to the direction toward the third flow path section to guide the particle other than the imaging target particle into the third flow path section.