  This article discusses the physics programme of the TOTEM experiment at the
LHC. A new special beam optics with beta* = 90 m, enabling the measurements of
the total cross-section, elastic pp scattering and diffractive phenomena
already at early LHC runs, is explained. For this and the various other TOTEM
running scenarios, the acceptances of the leading proton detectors and of the
forward tracking stations for some physics processes are described.
