A sealed, thermally insulated tank consists of tank walls fixed to the load-bearing structure of a ship, the tank walls having, in succession, in the direction of the thickness from the inside to the outside of the tank, a primary sealing barrier, a primary insulating barrier, a secondary sealing barrier and a secondary insulating barrier, at least one of the insulating barriers consisting essentially of juxtaposed non-conducting elements (3), each non-conducting element including a thermal insulation liner, at least one panel and load-bearing partitions rising through the thickness of the thermal insulation liner in order to take up the compression forces. These partitions include at least one anti-buckle partition (14) that includes a plurality of anti-buckle wall elements that have a respective orientation forming an angle relative to a general longitudinal direction of the anti-buckle partition, for example forming corrugations or double-wall portions.