SUPERMEMBRANES AT NONZERO TEMPERATURE

We review the thermodynamical properties of the (super)membranes in ca nonical ensemble. The free energy for flat supermembranes and for comp actified supermembranes is calculated in semiclassical approximation. The corresponding extension for super-p-branes is also presented. The presence of the Hagedorn temperature which depends on the cut-off para meter is found. It is shown that the free energy for (super)membranes can be presented in modular invariant form (SL(2, Z) invariance). Some connected problems (the calculation of the static potential, the prob able dual symmetry) for bosonic p-brane are also discussed.