Double-walled thermal container, comprising a first inner vessel (2) made of metallic material with a closeable first upper opening (5), inserted in a second outer vessel (7), also made of metallic material, which has a second opening (10). The two vessels (2 and 7) are mutually connected by virtue of a connecting assembly (11) which is arranged proximate to the openings (5, 10) so as to form, between the two vessels (2, 7), an interspace (12) in which vacuum is produced. The connecting assembly (11) is constituted exclusively by parts (13, 18) made of nonmetallic and thermally insulating material so as to form an effective hermetic heat barrier between the two vessels (2, 7). Another aspect of the invention provides for a method for manufacturing thermal containers having a double metal wall with relatively modest costs.