The design parameters, special features, and certain fabrication and test aspects of the TFTR vacuum vessel are described. The vessel is a single walled, stainless steel toroidal shell, designed for a base pressure of 10−8 Torr. The design basis includes the electromagnetic loads resulting from the disruption of a 3 MA plasma in a 5.2 T magnetic field. The vessel is configured to permit maximum access for neutral beam injection and diagnostic equipment. In addition, it is designed so that a segment of the machine can be removed and replaced using remote maintenance techniques. During the fabrication special processes were used to ensure cleanliness, achieve dimensional control, and perform in‐process vacuum tests.