Abstract: A lighting installation for interior lighting of structures with pneumatic supporting members, comprising a hollow slotted light guide in the form of a supporting and shaping element of the structure. The hollow slotted light guide is of elastic film with a mirror light-reflecting coating provided on a portion of the interior surface over the entire length thereof. The other portion, which faces the interior being lighted, is a light-permeable slot. The luminous flux from one or more light sources arranged in an optical input device, which is mounted at least on one side of the light guide, is directed into the light guide, multiply reflected from the internal surface which has a light-reflecting coating and escapes through the optical slot into the interior of the structure to be lighted.