<p>A heat-insulating window pane comprises at least one cavity which has no communication with the external faces of the pane. The cavity is evacuated to a gas pressure below 0.1 mbar. There are bridging members in the cavity. These bridging members extend transversely of the pane. The pane is easy to handle and its transparency properties are good because the cavity extends approximately to the marginal portions of the pane and occupies less than 20% of the total volume of the pane. The total area of the bridging members in a lengthwise section through the glass covers less than 10% of the area of the pane. The pane is relatively cheap to produce and does not constitute a risk of implosion because of the low volume of the cavity.</p>
