This book is the result of the teaching provided by the author within the university center Salhi Ahmed of Naâma. This course is intended for students in L3 mathematics and it is part of the official program of the subject of equations of mathematical physics.This subject aims to introduce the student to the study of partial differential equations (PDE). It teaches some analytical methods for solving PDEs; in particular, those modeling physical phenomena. From a practical point of view, you will find simple resolutions of many problems: continuity equation of electric charge, heat equation, wave equation, Laplace equation, Schrödinger equation.