According to one embodiment, an electrode (3, 5) is provided. The electrode (3, 5) includes an active material-containing layer (3b, 5b). The active material-containing layer (3b, 5b) includes an active material and a conductive agent. The active material contains primary particles (PP) of a niobium-titanium composite oxide. The conductive agent contains fibrous carbon (FC). The primary particles (PP) have an average particle size of 0.3 µm or more and 2 µm or less. At least a part of a surface of the primary particles is coated with the fibrous carbon. A covering ratio of the primary particles by the fibrous carbon is 0.01% or more and 40% or less.