According to one embodiment, there is provided an active material including particles of a composite oxide having an orthorhombic crystal structure and represented by the general formula Li2+wNa2−xM1yTi6−zM2zO14−δ. The particles of the composite oxide have an average crystallite size of 50 nm to 90 nm and an average primary particle size of 0.1 μm to 0.6 μm. M1 is at least one selected from the group consisting of Cs and K. M2 is at least one selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Fe, Y, Co, Mn, and Al. w falls within 0≤w≤4, x falls within 0