1. Introduction
2. Quantum statistical mechanics
3. The scalar field at finite temperature
4. Simple applications of perturbation theory
5. Dirac and gauge fields at finite temperature
6. Collective excitations in a plasma
7. Hard thermal loops and resummation
8. Dynamical screening
9. Neutrino emission from stars
10. Infrared problems at finite temperature
A Formulary
B Operator formalism

Relativistic thermal field theory gives the theoretical framework for the description of the quark-gluon plasma, a new state of matter whose existence is predicted by lattice gauge theory and which might be produced in collisions of ultrarelativistic heavy ions. It is also relevant for the description of some astrophysical processes and for the history of the early Universe