A controlled environment enclosure provides a dust-free atmosphere for manufacturing operations. The enclosure includes a frame formed of interconnected, horizontally and vertically extending, spaced frame members. An outer cover member is deployed over the sides and top of the interconnected frame members. The outer cover member is formed of a heat shrinkable material which provides a taut, secure attachment of the cover member to the frame members. The bottom ends of the cover member are sealingly attached to a lower support surface or floor by means of an interconnectable clamp and strip having a mating projection and notch which traps the bottom end of the cover member therebetween.