insect cells (spodoptera frugiperda) have been cultured in a stationary bed reactor packed with a fibrous polyester carrier. when the bioreactor was perfused with serum-supplemented medium, a cell density of 6 $multiplied by$ 10**6 cells ml** $minus$ **1 packed carrier was reached. scanning electron microscopy investigations have shown that the insect cells grew along the three-dimensionally oriented fibers of the fibra-cel carrier. after infection of the logarithmically growing cells with a recombinant baculovirus (autographa californica) containing the gene coding for $beta$ -galactosidase, the medium in the bioreactor was changed to serum-free medium. at day 13 postinfection (p.i.), a $beta$ -galactosidase level of 320 $mu$ g ml** $minus$ **1 and, at day 17 p.i., a virus titer of 2.1 $multiplied by$ 10**8 tcid//5//0 units ml** $minus$ **1 (day 17 p.i.) were reached. in another bioreactor, operated in a similar way but with serum-containing medium, a $beta$ -galactosidase concentration of 360 $mu$ g ml** $minus$ **1 and a virus titer of 2.3 $multiplied by$ 10**8 tcid//5//0 units ml** $minus$ **1 were obtained. these results indicate the potential use of this production system for the production of recombinant protein and baculovirus in insect cells. (author abstract) 34 refs