The Schwinger effect is known as a non-perturbative phenomenon in quantum electromagnetic dynamics (QED). The virtual electron-positron pairs can be created as real particles due to the presence of a strong electric field. Recently, Semenoff and Zarembo have proposed a setup to consider the Schwinger effect in the context of the AdS/CFT correspondence. In this talk, after a review of the setup, I will explain a generalization to include magnetic field. I also give another support for the proposal of Semenoff and Zarembo from the viewpoint of quark-antiquark potentials. This talk is based on the collaboration with Yoshiki Sato (Dept. of Phys., Kyoto Univ.) arXiv:1303.0112, 1304.7917.