This paper introduces the *Mathematica* package *FeynArts*, which is used for generating and visualizing Feynman diagrams and amplitudes. The main features of version 3 include three levels of diagram generation, user-definable model files, support for supersymmetric models, and publication-quality diagrams in PostScript or LaTeX. The program works in three steps: creating topologies, inserting fields, and applying Feynman rules to produce amplitudes. *FeynArts* supports various models, including the electroweak Standard Model, QCD, and soon the Minimal Supersymmetric Standard Model. The paper also discusses the concepts behind diagram generation, such as field levels and the flipping-rule algorithm for supersymmetric theories. The package is available for download and requires Mathematica 3 or above, along with a Java VM and J/Link for the topology editor.This paper introduces the *Mathematica* package *FeynArts*, which is used for generating and visualizing Feynman diagrams and amplitudes. The main features of version 3 include three levels of diagram generation, user-definable model files, support for supersymmetric models, and publication-quality diagrams in PostScript or LaTeX. The program works in three steps: creating topologies, inserting fields, and applying Feynman rules to produce amplitudes. *FeynArts* supports various models, including the electroweak Standard Model, QCD, and soon the Minimal Supersymmetric Standard Model. The paper also discusses the concepts behind diagram generation, such as field levels and the flipping-rule algorithm for supersymmetric theories. The package is available for download and requires Mathematica 3 or above, along with a Java VM and J/Link for the topology editor.