Volume 4 of the textbook on experimental physics covers the material of the fourth semester in the physics program. As with the first three volumes, the author presents the content in an easily understandable manner, while keeping it as quantitative as possible and tailored to the bachelor's degree program. Worked examples and exercises with detailed solutions assist in mastering the material and encourage active engagement. The completely revised new edition has been expanded to include sections on topics such as the LHC accelerator, extrasolar planets, and dark matter.