Liquid ejection apparatus and liquid ejection head

A liquid ejection apparatus in which a liquid ejection head provided with a recording element substrate having ejection orifices formed in one surface of the recording element substrate as well as a first liquid chamber and a second liquid chambers respectively communicating with the ejection orifices and with a support member supporting the other surface of the recording element substrate is mounted with the ejection orifices directed downward, wherein each of the first and second liquid chambers has an opening formed in the other surface, the support member has a first liquid storage portion, a second liquid storage portion, a first communication path extending from the first liquid storage portion to the opening of the first liquid chamber and a second communication path extending from the second liquid storage portion to the opening of the second liquid chamber, each of the first and second communication paths contains a flow path portion having a horizontal cross-sectional area smaller than the areas of the openings of the first and second liquid chambers, each of the flow path portions being connected to one of the first and second liquid storage portions in such a manner that an interior space of each of the first and second liquid storage portions is narrowed down,

• wherein a length of the flow path portion of the first communication path is longer than a length of the flow path portion of the second communication path, and the first liquid storage portion is more distant from the recording element substrate than the second liquid storage portion, and
• wherein the horizontal cross-sectional area of the flow path portion of the first communication path is larger than the horizontal cross-sectional area of the flow path portion of the second communication path.