To provide a glass pane for a window which is enhanced in thermally insulating performance, is thin and has a thermally insulating effect by sandwiching a sheet having a vacuum layer between two glass panes.

The vacuum layer is made by superposing, face to face, sheets (1) made of transparent and elastic plastic provided with a plurality of belt-like projections, hermetically sealing the circumferences of sheets (2) superposed double and further removing the air therein to create a vacuum state. The sheet (3) having such vacuum layer is sandwiched between the two glass panes (4). The double-layered glass sheet holding the vacuum layer in-between is made by constituting the glass sheet in the manner described above. The shapes of the cross sections of the belt-like projections of the sheets (1) are nine kinds in addition to a triangular shape.