Abstract: A spacer made of plastic material for building components, having at least two spaced apart panes that are fixedly connected to one another, consists of a hollow profiled member that is positioned between the panes. The hollow profiled member has sidewalls facing the panes, an interior wall facing the interior chamber between the panes, and an exterior wall facing outwardly. At least one first insert for inhibiting water vapor diffusion is provided. The at least one first insert is embedded in the sidewalls and the exterior wall. A second insert is embedded in the interior wall and is preferably of a material that inhibits water vapor diffusion, preferably a thin-walled foil made of metal or plastic.