An electronic device includes a case, a control module, a plurality of heat sinks and at least one airflow guiding structure. The case includes a bottom plate, a top plate, and at least one side plate. The bottom plate has a plurality of bottom holes for guiding air into the case. The top plate has a plurality of top holes for exhausting air in the case. The side plate connects the top plate and the bottom plate and has a plurality of side holes for exhausting air in the case. The control module is disposed in the case. The heat sinks are thermally connected to the control module. The airflow guiding structure is disposed between the heat sinks for guiding a part of the air in the case to the exterior of the case through the side holes.