Microstructures in rocks contain a wealth of information on the history of rock bodes, metamorphic and tectonic processes and the mechanical and rheological properties of the crust and mantle. The book deals with the numerical simulation of such microstructures in rocks. It starts with a general introduction of existing methods and techniques for optical and electron microscopic analysis and measurement of microstructure. The main part of the book contains a number of examples of numerical modelling of processes and microstructures in rocks, using the software package "ELLE". With the accompanying CD, readers can do these simulations themselves and run their own simulations.The book is targeted to a readership from the Earth sciences, from the level of MSc students and upwards. Each method presented will have some suggestions for further reading, referring to textbooks and scientific literature. The book will be a useful resource for lectures and numerical practicals on rheology, microscopy, petrology, structural geology, etc. It should be the "starting package" for students and researchers of the earth science community interested in numerical modelling of microstructures and anyone intending to work with ELLE.