PURPOSE: A multistage impacter for a low flow rate having a micro channel, and a manufacturing method thereof are provided to form a nozzle with a micro channel having a micro-unit or nano-unit cross section, and to collect particles effectively at a lower flow rate by forming a nozzle through a lithographic process. CONSTITUTION: A manufacturing method of a multistage impacter for a low flow rate having a micro channel comprises the steps of: coating a photosensitive polymer on a substrate (S10); soft-baking the coated photosensitive polymer (S20); exposing by using a mask having a pattern for multiple flowing spaces and nozzles divided into multistage, an inlet, and an outlet (S30); removing the photosensitive polymer corresponding to the outlet discharging the fluid, the inlet inducing the fluid, the multiple nozzles connecting the flowing spaces, and the flowing spaces divided into multistage by developing (S40); forming a side wall unit by hard-baking the residual photosensitive polymer (S50); and combin
