The invention relates to a mat which is produced on the warp-knitting principle with the use of foil webs and textile threads and is used for heat insulation, preferably in greenhouses. According to the invention, the foil webs consist of biaxially stretched foil with a very low splicing tendency and are sewn over with the textile threads in a right/left fringe weave. At the same time, the stitch-wale spacing is at least 10 mm and the stitch length at least 2 mm. At least two foil webs are creased. The mat can have reflection means and contain additional longitudinal and/or transverse threads. The construction and choice of material guarantee the formation of sufficiently large air inclusions and good stability.
