To provide a heat insulation panel suitable for a refrigeration car whose heat insulation effect is not reduced by water absorption and whose members are not corroded.

In a heat insulation panel formed of material which does not absorbs water, shells 4c each of which forms a closed space independently separated from each other are uniformly distributed and light-reflecting layers 2a, 4d are formed on the inner walls of each shell 4c and the closed space is made vacuum to prevent heat transfer caused by convection and radiation by the shell 4c, which improves a heat insulation effect. Since the shells 4c each of which is formed like a honeycomb are uniformly distributed, even if part of them are broken, remaining groups of shells 4c can keep a heat insulation performance.