A liquid ejection head comprising: a substrate having a first surface and a second surface opposite to the first surface; a circulation channel provided on a side of the first surface of the substrate; a plurality of pressure chambers provided on the side of the first surface of the substrate, liquid being circulated through the pressure chambers; and a plurality of ejection energy generating elements provided on the side of the first surface of the substrate, each of the ejection energy generating elements generating energy for ejecting liquid in the respective pressure chamber from an ejection port of the liquid ejection head, said ejection energy generating elements are electrothermal transducers or heaters, and said ejection port is provided to correspond to each of the pressure chambers, wherein the pressure chambers are provided in series in the circulation channel; and wherein the circulation channel includes said plural pressure chambers, and the circulation channel is connected to a first supply path configured to supply liquid, having a first pressure, to a first position of the circulation channel, and a second supply path configured to supply liquid, having a second pressure different from the first pressure, to a second position of the circulation channel different from the first position, wherein the substrate includes: a penetration supply path configured to penetrate between the first surface and second surface of the substrate so as to supply liquid to the circulation channel; and a penetration recovery path configured to penetrate between the first surface and second surface of the substrate so as to recover liquid from the circulation channel, wherein the first position is one end of the circulation channel and comprises a first connection port of the first supply path whereas the second position is the other end of the circulation channel and comprises a second connection port of the second supply path, wherein the penetration supply path is open to the second supply path, and the penetration recovery path is open to the first supply path, and the ejection ports and the pressure chambers are formed at positions opposite to the ejection energy generating elements. a substrate having a first surface and a second surface opposite to the first surface; a circulation channel provided on a side of the first surface of the substrate; a plurality of pressure chambers provided on the side of the first surface of the substrate, liquid being circulated through the pressure chambers; and a plurality of ejection energy generating elements provided on the side of the first surface of the substrate, each of the ejection energy generating elements generating energy for ejecting liquid in the respective pressure chamber from an ejection port of the liquid ejection head, said ejection energy generating elements are electrothermal transducers or heaters, and said ejection port is provided to correspond to each of the pressure chambers, wherein the pressure chambers are provided in series in the circulation channel; and wherein the circulation channel includes said plural pressure chambers, and the circulation channel is connected to a first supply path configured to supply liquid, having a first pressure, to a first position of the circulation channel, and a second supply path configured to supply liquid, having a second pressure different from the first pressure, to a second position of the circulation channel different from the first position, wherein the substrate includes: a penetration supply path configured to penetrate between the first surface and second surface of the substrate so as to supply liquid to the circulation channel; and a penetration recovery path configured to penetrate between the first surface and second surface of the substrate so as to recover liquid from the circulation channel, wherein the first position is one end of the circulation channel and comprises a first connection port of the first supply path whereas the second position is the other end of the circulation channel and comprises a second connection port of the second supply path, wherein the penetration supply path is open to the second supply path, and the penetration recovery path is open to the first supply path, and the ejection ports and the pressure chambers are formed at positions opposite to the ejection energy generating elements. a penetration supply path configured to penetrate between the first surface and second surface of the substrate so as to supply liquid to the circulation channel; and a penetration recovery path configured to penetrate between the first surface and second surface of the substrate so as to recover liquid from the circulation channel, wherein the first position is one end of the circulation channel and comprises a first connection port of the first supply path whereas the second position is the other end of the circulation channel and comprises a second connection port of the second supply path, wherein the penetration supply path is open to the second supply path, and the penetration recovery path is open to the first supply path, and the ejection ports and the pressure chambers are formed at positions opposite to the ejection energy generating elements.