Introduction -- Sensors and Sensors Science -- Chemical sensors -- Fundamentals -- Sensor physics -- Sensor chemistry -- Sensor technology -- Measurement with sensors -- Semiconductor structures as chemical sensors -- Mass sensitive sensors -- BAW sensors -- SAW sensors -- Conductivity sensors and capacitive sensors -- Conductometric sensors -- Resistive and capacitive gas sensors -- Resistive and capacitive sensors for liquids -- Thermometric and calorimetric sensors -- Sensors with thermistors and pellistors -- Pyroelectric sensors -- Sensors on the basis of further thermal effects -- Electrochemical sensors -- Potentiometric sensors -- Amperometric sensors -- Sensors based on other electrochemical methods -- Electrochemical biosensors -- Optical sensors -- Optical fibres as a basis for optical sensors -- Fibre sensors without chemical receptors (mediators) -- Optodes: fibre sensors with a chemical receptor -- Sensors with planar optical transducers -- Optical biosensors -- Sensor systems with integrated optics -- Chemical sensors as detectors and indicators -- Indicators for titration processes -- Flow-through detectors for continuous analysers and for separation techniques -- Sensor arrays and micro total analysis systems -- Two trends and their reasons -- Smart sensors and sensor arrays -- Micro Total chemical Analysis Systems (µ-TAS).