Per its namesake, the facility is a spherical structure containing a powerful Kojima reactor. The Sphere is defended by the famed Silent Avalanche unit, who have defended Sphere from multiple attempts by other companies to seize the facility.
By the time of Armored Core: For Answer, the Sphere has been expanded to include several additional Sphere facilities.
- The Sphere Facility is erroneously referred to as belonging to Omer in the briefing of the ACFA mission "Ambush Sphere Invasion Forces." This arose from a minor mistranslation, and Omer was in fact the force attacking the Sphere.