A cabinet includes a base, a top frame, at least three vertical pillar assemblies which are disposed between the base and the top frame, a cover, and at least three side plates. The cover is disposed at a side of the top frame, that is opposite to the side facing the base. A vertical pillar assembly includes a pillar, an inner clamp, and an outer clamp, wherein the inner clamp includes a first and a second side edge, and the outer clamp includes a third and a fourth side edge. The pillar is clamped between the inner clamp and the outer clamp. Space between the first side edge and the third side edge of the outer clamp is used for clamping a side plate, and space between the second side edge and the fourth side edge of the outer clamp is used for clamping a side plate.