The present invention relates to a catalytic device for the implementation of a reaction in a gaseous medium at high temperature, such as, for example, the synthesis of HCN or the oxidation of ammonia, comprising: at least one textured material (1) which is effective as catalyst for the said reaction, a support (2) comprising at least one ceramic part (3), the structure of which makes possible the passage of the gases, the said part (3) of the said support (2) having a corrugated face (6), so that the increase in surface area (.beta.) produced by the corrugations with respect to a flat surface is at least equal to that (.alpha.) calculated for sawtooth corrugations and of between approximately 1.1 and approximately 3, the said textured material (1) being positioned so that it is held against the corrugated face (6) of the said part (3) of the said support (2) and follows the form thereof.