A heat insulating container is described, including an outer glass container
and
an inner glass container housed therein with a gap formed in-between as a heat
insulating layer. A radiant heat preventive film containing a metal oxide is disposed
on at least one of the external surface of the inner container or the internal
surface of the outer container, wherein the radiant heat preventive film has a
reflectivity of 35% or higher with a wavelength of 15 m. When the thickness
of the radiant heat preventive film is 3000 , the Hall mobility "x" (cm2/Vs)
and the carrier concentration "y" (cm-3) of the same satisfy the following
formulae: y-51020x+21021 and y-61018x+31020.
When the thickness of the radiant heat preventive film is 5000 , x and
y satisfy the following formulae: y-51020x+31021
and y-61018x+71020. Such radiant
heat preventive films can have high reflectivity.