The 2007 ESO Instrument Calibration workshop brought together more than 120 participants with the objective to a) foster the sharing of information, experience and techniques between observers, instrument developers and instrument operation teams, b) review the actual precision and limitations of the applied instrument calibration plans, and c) collect the current and future requirements by the ESO users.
These present proceedings include the majority of the workshop¿s contributions and document the status quo of instrument calibration at ESO in large detail. Topics covered are: Optical Spectro-Imagers, Optical Multi-Object Spectrographs, NIR and MIR Spectro-Imagers, High-Resolution Spectrographs, Integral Field Spectrographs, Adaptive Optics Instruments, Polarimetric Instruments, Wide Field Imagers, Interferometric Instruments as well as other crucial aspects such as data flow, quality control, data reduction software and atmospheric effects.
It was stated in the workshop that ¿calibration is a life-long learning process¿'. In this sense, this book will be a reference point for all future efforts to improve instrument calibration procedures in astronomy.

Part I Introduction.- Part II Session 1: Optical Spectro-Imagers.- Part III Session 2: Optical Multi-object Spectrographs.- Part IV Session 3: Near-IR and mid-IR Spectro-Imagers.- Part V Session 4: Data Flow and Data Reduction Software.- Part VI Session 5: Adaptive Optics Instruments.- Part VII Session 6: Integral Field Spectroscopy.- Part VIII Session 7: High Resolution Spectroscopy.- Part IX Session 8: Atmospheric Effects.- Part X Session 9: Interferometric Instrumentation.- Part XI Session 10: Polarimetry.- Part XII Session 11: Wide Field Imagers.- Part XIII Workshop Summary.