Boundary integral equations are reformulations of partial differential equations with non-local integral operators. Widely used in acoustics, electromagnetism and mechanics, they have the advantage to reduce the dimension of the geometric domain and they naturally satisfy conditions at infinity for problems on unbounded domains. But the matrices obtained after discretisation have the disadvantage to be dense, so that iterative linear solvers, such as conjugated gradient or GMRes, are usually preferred compared to direct solvers. To stabilise the number of iterations of these solvers with respect to the mesh size, a classical technique is to use a preconditioner. In this talk, I will first introduce domain decomposition methods and boundary integral equation, and then I will present how to precondition the matrices stemming from the boundary element method using domain decomposition methods, and more precisely, Schwarz Methods with a particular coarse space named GenEO whose construction is based on Generalized Eigenproblems in the Overlaps. This is a joint work with Xavier Claeys and Frédéric Nataf.