The book is the result of some years of teaching a course in Physics Modeling in Economics and Finance to M.Sc. students of Physics/Astrophysics and Eng. Physics. It is devoted to show economics and finance as a part of a physics system by its own right and, with that, to provide students with the basic tools to face a career in finance or in research developing physics models to a very unusual system that we call “an economy,” but made of interactions, geometry, equilibrium, and inflation. It goes from understanding the fundamental of basic mathematics to explaining complex systems where it stops working; from the physics’ meaning of money to derivative valuation; and from statistical physics to the physics of inflationary systems.