The Fredrickson-Andersen one spin facilitated model (FA-1f) on Z belongs to the class of kinetically constrained spin models (KCM). Each site refreshes with rate one its occupation variable to empty (respectively occupied) with probability q (respectively p = 1 − q), provided at least one nearest neighbor is empty. Here, we study the non equilibrium dynamics of FA-1f started from a configuration entirely occupied on the left half-line and focus on the evolution of the front, namely the position of the leftmost zero. We prove, for q larger than a thresholdq < 1, a law of large numbers and a central limit theorem for the front, as well as the convergence to an invariant measure of the law of the process seen from the front.Let Ω = {0, 1} Z be the space of configurations andbe the subspace of configurations with a leftmost zero at the origin. For a configuration σ for which there exists x ∈ Z such that for every y < x, σ(y) = 1 and σ(x) = 0, we call x the front of configuration σ and we denote it by X(σ). For Λ ⊂ Z and σ ∈ Ω, we denote by σ Λ the restriction of σ to the set Λ. For σ ∈ Ω and x ∈ Z, let σ x be the configuration σ