A non-aqueous electrolyte secondary battery includes an electrode assembly formed by winding positive and negative electrodes, and an insulating layer together. Each of the electrodes has a core sheet and mixture layers formed on both sides of the sheet. The insulating layer electrically insulates the electrodes. At least one of the electrodes includes a core-exposed portion continuous parallel to the winding direction. Each of the mixture layers has an inclined weight region where the amount of mixture per unit area decreases toward the core-exposed portion, and a constant weight region in which the amount of mixture per unit area is constant. The inclined weight region has a width of not more than 0.2 of the width of the mixture layers and has an average mixture density of not less than 40% and not more than 99% of the mixture density of the constant weight region.