A negative electrode material includes at least a graphite particle and a first metal oxide. The graphite particle includes at least one open pore. The graphite particle has a porosity not lower than 13% and not higher than 66%. The first metal oxide adheres to an inner wall of the open pore. The first metal oxide is lithium ion conductive and electron conductive. The first metal oxide is not smaller than 0.5 part by mass and not greater than 20 parts by mass with respect to 100 parts by mass of graphite particle.