A Plasma torch (10) for microwave induced plasma spectrochemical analysis of a sample includes a nozzle (30) in an inlet (18) for the main plasma gas flow between outer tube (12) and intermediate tube (14) of the torch (10). The nozzle (30) increases the gas flow velocity in the sheathing gas layer for the plasma which is provided by the gas flow from the annular gap (22) between the tubes (12 and 14). The increased velocity of the gas in the sheathing gas layer "stiffens" that layer and thus better confines the microwave induced plasma (such better confinement not being necessary for an ICP torch). Thus the torch is of improved durability for a microwave induced plasma compared to an ICP torch. The sample injection (inner) tube (16) may have a reduced diameter outlet at its end (34) which is substantially level with the end (35) of intermediate tube (14) to improve injection of a sample into the microwave induced plasma. The inlet end (26) of the sample injection tube (16) may include a heater (36) to assist in preventing blockages in tube (16) near its outlet end.