[en] The phase transition of 4D simplicial quantum gravity coupled to U(1) gauge fields is studied using Monte-Carlo simulations. The phase transition of the dynamical triangulation model with a vector field (Nv = 1) is smooth compared with pure gravity(Nv = 0). The node susceptibility (χ) is studied by the finite size scaling method. At the critical point, the node distribution has a sharp peak in contrast to the double peak in pure gravity. From the numerical results, we expect that 4D simplicial quantum gravity with U(1) vector fields has a higher order phase transition than 1st order, which means the possibility to take the continuum limit at the critical point