  A master equation for the deformed quantum harmonic oscillator interacting
with a dissipative environment, in particular with a thermal bath, is derived
in the microscopic model by using perturbation theory. The coefficients of the
master equation and of equations of motion for observables depend on the
deformation function. The steady state solution of the equation for the density
matrix in the number representation is obtained and the equilibrium energy of
the deformed harmonic oscillator is calculated in the approximation of small
deformation.
