The production of cellular filler from glass-reinforced thermoplastic composite by the method of continuous molding which allows to make filler for laminate panels of “sandwich” type with width up to 700 mm, length limited with size of the production facilities, and height from 5 to 20 mm. The developed technology eliminates the usage of solvents and reduces labor input of production 3 times as compared with production of traditional honeycomb fillers.