diff --git a/cachematrix.R b/cachematrix.R
index a50be65aa44..984b4015232 100644
--- a/cachematrix.R
+++ b/cachematrix.R
@@ -1,15 +1,46 @@
-## Put comments here that give an overall description of what your
-## functions do
+## The 2 functions permit to create a special object that stores a matrix and
+## its inverse.
 
-## Write a short comment describing this function
+## The makeCacheMatrix() function returns a list of 4 fonctions
+## and each of these functions returns a matrix.
 
 makeCacheMatrix <- function(x = matrix()) {
-
+        inv<-NULL
+        
+        ## 1. set() function permits to store 
+        ##   the matrix that one want to compute inverse.
+        set<-function(y){
+                x<<-y
+                inv<<-NULL
+        }
+        
+        ## 2. get() function returns the initial matrix.
+        get<-function(){x}
+        
+        ## 3. setInv() permits to sore the inverse in the Inv variable 
+        ## that is in the closure of makeCacheMatrix().
+        setInv<-function(m){
+                inv<<-m
+        }
+        ## 4. getInv() returns the inverse of the initial matrix x.
+        getInv<-function() {inv}
+        list(set=set,get=get,setInv=setInv,getInv=getInv)
 }
 
 
-## Write a short comment describing this function
+## The function takes the input x (matrix)
 
 cacheSolve <- function(x, ...) {
         ## Return a matrix that is the inverse of 'x'
+        ## Take the value of the inverse of x
+        inv<-x$getInv()
+        ## Check if inv is NULL or not
+        if(!is.null(inv)){
+                return(inv)
+        }
+        ## Here, we get the initial matrix, compute his inverse and store it
+        mat<-x$get()
+        inv<-solve(mat)
+        x$setInv(inv)
+        inv
 }