This invention provides an electrode for a lithium ion rechargeable battery that, even when exposed to severe conditions, for example, in a nail piercing test or a collapse test, can ensure a high level of safety and also has excellent output characteristics. Specifically, there is provided an electrode for a lithium ion rechargeable battery, comprising a mixture containing active material particles, which can reversibly occlude and release lithium, and a current collector for supporting the mixture, wherein the surface of the current collector has a concave part, and not less than 30% of themixture support area of the current collector is accounted for by the concave part. There is also provided an electrode for a lithium ion rechargeable battery in which, in a cross section formed by simultaneously cutting a mixture and a current collector perpendicularly to the electrode face, the maximum depth of the concave part is not less than 1 mum, or the difference between the average thickness of the current collector and the maximum thickness of the current collector is not less than 0.35 mum.