A computer enclosure includes a fan, a base and a cover. The base includes a support plate. The support plate defines a plurality of air vents. The fan is located on a bottom side of the support plate, and a plurality of operating components is mounted on a top side of the support plate. The cover is mounted on the top side of the support plate to enclose the plurality of operating components. The cover includes a top plate. The top plate defines a plurality of air vents cooperating with the air vents of the support plate to form an air flowing channel.