The author introduces a summability method of power series in several variables, and investigates applications to formal solutions of singular perturbation problems and partial differential equations. The sum of a formal power series \(\widehat{f}\) in finitely many variables \(z_1, z_2,\dots,z_m\) is expressed as \[ f(z_1, z_2, \ldots, z_m) = \int_0^{\infty} e^{-x} g(x^{s_1}z_1, x^{s_2}z_2,\dots, x^{s_m}z_m) \,dx \] for some function \(g\) holomorphic near the origin. By introducing suitable new variables depending on \(s_1, s_2, \dots, s_m\) it turns out that the application of the Borel and Laplace transform only applies to a single variable instead of affecting all variables at a time.