To provide a nonaqueous electrolyte battery in which stability at high temperature is secured without changing a battery design and without lowering charge/discharge characteristics and an adverse effect of hydrogen fluoride generated by hydrolysis or the like of lithium salt especially is suppressed.

The nonaqueous electrolyte battery includes an anode having a carbon material capable of doping/undoping lithium as an anode active material, a cathode having a composite oxide with lithium and a transition metal as a cathode active material, and a nonaqueous electrolyte solution. The nonaqueous electrolyte solution contains 0.001 wt.% or more and 5 wt.% or less of diamine compound having two amino groups capable of performing an interaction with proton, and the diamine compound has a structure in which an angle made by two nitrogen atoms in the amino group and the proton may become 155 degrees or more and 180 degrees or less when the compound is made to interact with the proton.