According to one embodiment, an electrode is provided. The electrode includes an active material-containing layer. The active material-containing layer includes an Na-containing niobium-titanium composite oxide having an orthorhombic crystal structure. The active material-containing layer satisfies I2/I1≥1. I1 is an intensity of a peak P1 appearing in a binding energy range of 289 eV to 292 eV in an X-ray photoelectron spectroscopy spectrum of the active material-containing layer. I2 is an intensity of a peak P2 appearing in a binding energy range of 283 eV to 285 eV in the X-ray photoelectron spectroscopy spectrum of the active material-containing layer.