Formulation of Matrix Theory at Finite Temperature

The interaction between static D0-branes at finite temperature is considered in the matrix theory and the superstring theory. The results agree in both cases to the leading order in the supersymmetry violation by temperature, where the one-loop approximation is reliable. The effective static potential is short-ranged and attractive. Talk at the 32nd International Symposium Ahrenshoop on the Theory of Elementary Particles, Buckow, Germany, September 1-5, 1998.