Disclosed is a micro particle analyzing device illuminating light to fluid including micro particles, reading the lights emitted from the micro particles at a signal processing reading section and thus analyzing the micro particles. The device comprises a light source section emitting light which will be illuminated to the fluid; a lens regulating an amount and a focal distance of the light emitted from the light source; and a concave mirror condensing light emitted from the micro particle to reflect it to the reading section wherein the concave mirror is formed with a hole so that the light of the light source section having passed through the lens can pass through the concave mirror. When analyzing the micro particles using the analyzing device according to the invention, the amounts of lights emitted from the micro particles according to up-and-down positions of the micro particles are not different.