A 0.2-08-mm H-, Na- or Ca-form Amberlite ICR-84 was dried at 383 K and pyrolyzed over 383-700 K at 5 K/min and then over 700-1000 K at 10 or 14 K/min in He or N atm. The chars were partly gasified with 20 mol% H2O + N-2 for 25 min. Ca was removed with 3M HCl. Up to 400 K, each resin was equally thermostable. Up to 700 K, the H- and the Na-forms lost 70% and the 0.5%Ca and the 5.9%Ca forms lost 65 and 20% in wt. The Ca-form was most effective as a precursor to a micro and mesoporous material, sp. surface 170-185 m(2)/g, pore size ca. 2 ml/g. The porous structure was related to the metal ion charge and to the ramp rate. Particle size of the starting resin was irrelevant.