five different beams are used by COMPASS: positive and negative muon beams with a nominal momentum of 160 GeV/c or 200 GeV/c, positive hadron beams with a nominal momentum of 190 GeV/c and a composition of 75% protons, 24% pions and 1% kaons, negative hadron beams with a nominal momentum of 190 GeV/c and a composition of 1% anti-protons, 97% pions and 2% kaons, low intensity electron beam for calibration purposes (60 and 40 GeV/c). Beam telescope The timing and the position of the incident particles are determined with cold silicon strip detectors and scintillating fibre detectors. These informations are crucial to determine the interaction point inside the target material. Depending on the beam type, modifications in the beam telescope are done: For the muon beam, the momentum is measured using beam momentum stations, To distinguish between the different particle types in the hadron beam, a Cherenkov detector is used. Target According to the physics goal, a suitable target is needed. For polarised physics, the spins of the target material need to be oriented in one direction. The target cell contains either ammonium or deuterium, which are polarised by the means of microwave radiation and strong magnetic fields. To keep up the polarisation grade, a 3He/4He dilution refrigerator is used to cool down the target material to 50 mK. The target material can be polarised longitudinal or transverse to the beam axis. For unpolarised physics, mostly liquid hydrogen is used, allowing to study the proton properties. For other physics, where high atomic numbers are needed, nickel, lead and other nuclear targets are used. The main advantage of a fixed target experiment is the large acceptance. Due to the Lorentz boost, most of the final states and the scattered particles are created along the beam axis. This leads to the distinctive set-up of a fixed-target experiment: most detectors are placed behind the target ("forward spectrometer"). For some processes it is necessary to detect the recoil nucleon from the target. Here, a recoil proton detector consisting of two barrels of scintillator material is used. The protons are identified by the time of flight and the energy loss. Spectrometer The COMPASS experiment consists of two spectrometer stages with various tracking detector types, each set-up around a spectrometer magnet to determine the momentum of the particles. The first stage is dedicated to tracks with large scattering (production) angles and the second one for small