The presence (or absence) of spin glass phase in uniform magnetic field is studied in the three and four dimensional Edwards–Anderson Ising spin glass. Effective coupling Jeff and effective field Heff of each sample are measured by a numerical renormalization-group method, and their sample-to-sample fluctuations σJ and σH are estimated for various sizes L and fields H. As found in the Migdal–Kadanoff spin glass, σJ and σH are scaled as a function of L/ℓ(H), where ℓ(H)=H-1/ζ is the so-called overlap length. Furthermore, our data show that the scaling function of σJ drops to zero in the limit L/ℓ(H)→∞. These results indicate the absence of spin glass phase even in an infinitesimal field.