We investigated the influence of the decomposition conditions (temperature: 500, 700, 900 degrees C, steam concentration: 0, 35, 86 vol%, Ca(OH)(2)/PC molar ratio: 0 or 5) on polycarbonate (PC). Without steam and Ca(OH)2 the liquefaction yield was 57 wt% (low and high boiling products 14, 43 wt%, respectively), the gasification yield 12 wt%, and the carbonization yield 31 wt% at 500 degrees C. At a steam concentration of 86 vol%, 84 wt% liquids (low and high boiling products 17, 67 wt%, respectively), 1 wt% gases and 15 wt% residues were observed. The amount of low boiling products increased from 17 to 31 wt%, and the amount of high boiling products decreased from 67 to 49 wt% when Ca(OH)(2) was added at a steam concentration 86 vol%. At this time, the yield of phenol in the low boiling fraction increased from 15 to 74 mol% (20 wt% of all products).