The present invention provides an impaction-based microorganism collecting device in which microorganisms are captured by the capture surface of a collection plate. The microorganism collecting device is designed to reduce the influence of the lateral wind flowing over the perforated plate having multiple nozzles and also prevent warpage of the perforated plate.Multiple air vents are formed around the circumference of the capture surface and through the capture surface so that air that has flowed through the nozzles of the perforated plate onto the capture surface can be discharged. This allows the air to flow in multiple directions over the capture surface, thereby reducing the speed of the air and increasing the microorganism capture rate.