A recently constructed generalised-Boltzmann statistical mechanics (a compl
ement to the Daroczy-Tsallis "non-extensive" statistics) is extended into t
he quantum domain. We introduce a control parameter kappa, postulate the ge
neralised collision integral and derive the generalised Fermi-Dirac and Bos
e-Einstein distribution functions for quantum gases in equilibrium. The ana
logy to the Boltzmann case proves the validity of the thermodynamic relatio
ns. The grand thermodynamic potential assumes a complicated but suggestive
form. The generalized Fermi gas has no real zero-temperature states. At T =
0 it becomes the ordinary Fermi gas. This is interpreted as destruction of
correlations as T --> 0. The low-temperature dependence of the control par
ameter kappa(T) is determined.