Pulverized fuel firing is the dominant application of supercritical steam cycles. This has been driven by the aims of efficiency improvement and reduction in environmental emissions. The sensitivity of supercritical steam plant to operating conditions is reviewed and the improvements in operating plant efficiency achieved through increase in steam pressure and temperatures and other factors such as auxiliary power demand is illustrated. Steam temperatures have increased by about 40°C during the 1990s and this, together with an increase in main steam pressure and cycle improvement, have led to a net efficiency of 45 per cent (reduced to UK conditions) for the state-of-the-art plant at present. Plants with still more advanced conditions are under construction or are planned, with the prospect of plant efficiency of 50 per cent in the future. This will rely on continued improvement in materials and is supported by a number of European programmes. Some main difficulties in the design of boilers with advanced temperatures, in particular steam temperature at the furnace outlet, furnace tube arrangement, and materials for superheater and reheater outlet sections, are discussed and the state of advanced steam turbines is reviewed. The operational availability of the supercritical plant, at least in Europe, has improved such that it is little different to the subcritical plant. Similarly, significant improvements have been made in controlling emissions by refinement of flue gas clean-up systems and combustion technology.