Abstract: The present invention relates to a vacuum insulation board (1) comprising: a hermetically closed covering (3) in which the pressure is lower than atmospheric pressure, a core material (5) made of organic aerogel placed inside said covering (3), said organic aerogel being based on a resin resulting at least in part from polyhydroxybenzene(s) R and formaldehyde(s) F, said organic aerogel being a polymeric monolithic organic gel comprising at least one water-soluble cationic polyelectrolyte, or said organic aerogel being a pyrolysate of said gel in the form of a porous carbon monolith comprising the product of the pyrolysis of said at least one water-soluble cationic polyelectrolyte P, said organic aerogel exhibiting a specific thermal conductivity of between 10 and 40 mW·m?1·K?1 at atmospheric pressure.