A server system comprising: a base; a front panel arranged on the base and having an external frame and an internal frame, wherein a collecting space is defined between the external frame and the internal frame; two doors, respectively arranged on opposite sides of the base, and being perpendicular to the front panel; two storage cases arranged between the doors in back to back arrangement, and configured to receive multiple rows and columns of a plurality of horizontally arranged storage drives at front of the two storage cases, wherein two first corridors parallel to each other are each defined between one of the doors and one of the storage case facing the one door, and the two storage cases are configured to receive the plurality of storage drives in such a way that every storage drive is at least partially exposed to one first corridor that is next to the storage drive; two circuit boards vertically arranged with respect to the base respectively, and respectively standing behind one of the two storage cases, wherein the two circuit boards comprise a plurality of slits, wherein a second corridor parallel to the two first corridors is defined between the two circuit boards; and a storage cover disposed above the base over the collecting space, the two first corridors, the second corridor, the two storage cases, and the two circuit boards; wherein: the base is configured to receive a fan unit arranged in a door to door direction; the fan unit is configured to introduce air from outside of the front panel and direct air to sequentially pass through the collecting space, the two first corridors, the two storage cases, the plurality of slits on the two circuit boards and the second corridor, and the storage cases are between the fan unit and the front panel. a base; a front panel arranged on the base and having an external frame and an internal frame, wherein a collecting space is defined between the external frame and the internal frame; two doors, respectively arranged on opposite sides of the base, and being perpendicular to the front panel; two storage cases arranged between the doors in back to back arrangement, and configured to receive multiple rows and columns of a plurality of horizontally arranged storage drives at front of the two storage cases, wherein two first corridors parallel to each other are each defined between one of the doors and one of the storage case facing the one door, and the two storage cases are configured to receive the plurality of storage drives in such a way that every storage drive is at least partially exposed to one first corridor that is next to the storage drive; two circuit boards vertically arranged with respect to the base respectively, and respectively standing behind one of the two storage cases, wherein the two circuit boards comprise a plurality of slits, wherein a second corridor parallel to the two first corridors is defined between the two circuit boards; and a storage cover disposed above the base over the collecting space, the two first corridors, the second corridor, the two storage cases, and the two circuit boards; wherein: the base is configured to receive a fan unit arranged in a door to door direction; the fan unit is configured to introduce air from outside of the front panel and direct air to sequentially pass through the collecting space, the two first corridors, the two storage cases, the plurality of slits on the two circuit boards and the second corridor, and the storage cases are between the fan unit and the front panel.