• F. Roncarolo, G. Bellodi, E. Bravin, B. Dehning, M. Duraffourg, G.J. Focker, D. Gerard, E.B. Holzer, LF. Lenardon, U. Raich, L. Søby, M. Sordet, J. Tan, G. Tranquille, VC. Vuitton, C. Zamantzas
  CERN, Geneva
• B. Cheymol
  Université Blaise Pascal, Clermont-Ferrand

The CERN LINAC4 will represent the first upgrade of the LHC injection chain, by accelerating H^- ions from 45 KeV to 160 MeV for charge-exchange injection into the PS Booster. In order to provide its safe and efficient commissioning and operation, a wide variety of beam diagnostics devices has been designed for installation at convenient locations all over the accelerator length and in the transfer line to the PS Booster. This paper gives an overview of all instrumentation devices, including those to measure beam position, transverse and longitudinal profile, beam current and beam loss. The well advanced status of the system design and the main instrument features are discussed.