An electrode for a lithium ion battery provided with a first principal surface located on a separator side of the lithium ion battery and a second principal surface located on a current collector side, wherein the electrode has a thickness of 50 to 5000 μm, the electrode comprises, between the first principal surface and the second principal surface, short fibers having an average fiber length of 50 nm or more and less than 100 μm, long fibers having an average fiber length of 110 μm or more and 1000 μm or less, and active material particles, while a binding agent is not included therein, the average fiber lengths being determined according to the methods specified in description paragraph, the short fibers and the long fibers are electroconductive fibers, and an average fiber diameter of the long fibers is 0.1 to 100 μm, the average fiber diameter of the long fibers being determined by SEM observation by measuring the diameter at or near the middle of each fiber for ten fibers having a fiber length of 110 μm or more and 1000 μm or less which are present in a 2 mm square field of view, performing this measurement for three fields of view, and taking the average of the diameters of a total of 30 fibers as the measured value, and wherein the active material particles are coated active material particles whose surface is at least partially coated with a coating agent containing a coating resin and a conductive aid, wherein the coating resin is selected from the group consisting of vinyl resins, urethane resins, polyester resins, polyamide resins, epoxy resins, polyimide resins, silicone resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonates. the electrode has a thickness of 50 to 5000 μm, the electrode comprises, between the first principal surface and the second principal surface, short fibers having an average fiber length of 50 nm or more and less than 100 μm, long fibers having an average fiber length of 110 μm or more and 1000 μm or less, and active material particles, while a binding agent is not included therein, the average fiber lengths being determined according to the methods specified in description paragraph, the short fibers and the long fibers are electroconductive fibers, and an average fiber diameter of the long fibers is 0.1 to 100 μm, the average fiber diameter of the long fibers being determined by SEM observation by measuring the diameter at or near the middle of each fiber for ten fibers having a fiber length of 110 μm or more and 1000 μm or less which are present in a 2 mm square field of view, performing this measurement for three fields of view, and taking the average of the diameters of a total of 30 fibers as the measured value, and wherein the active material particles are coated active material particles whose surface is at least partially coated with a coating agent containing a coating resin and a conductive aid, wherein the coating resin is selected from the group consisting of vinyl resins, urethane resins, polyester resins, polyamide resins, epoxy resins, polyimide resins, silicone resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonates.