The novel heat-insulating body is composed of at least two smooth, heat-radiation-deflecting sheets (1) which are spaced apart uniformly from one another. Spacers (2) in the form of a regular grid structure of uniform thickness are arranged between the sheets (1). There are further provided means for holding sheets and the spacers together in a largely convection-tight manner, e.g. an adhesive-bonding connection. The maximum spacing (d) between mutually adjacent sheets (1) is equal to or less than 5 mm, and the largest lateral extent of the grid divisions (2.0) is approximately 20 times the maximum sheet spacing. Consequently, very good heat-insulating properties with low equivalent coefficients of thermal conductivity are achieved. <IMAGE>
