Liquid ejection substrate and liquid ejection head

A liquid ejection head comprising:

• a liquid ejection substrate including:
• a base substrate having a flow path formed therein, the base substrate including an energy generation element configured to generate energy for ejecting a liquid;
• and
• an ejection port forming member having a first surface facing an outside of the liquid ejection substrate and a second surface on an opposite side to the first surface, the second surface facing the base substrate, the ejection port forming member having an ejection port penetrating from the first surface to the second surface, the ejection port forming member being arranged on the base substrate such that the ejection port overlaps the energy generation element as viewed in a direction orthogonal to the first surface, and being configured to transmit light;
• and
• a support member configured to support the liquid ejection substrate, wherein
• a depressed portion having a minimum opening width of at least 1 μm and a depth of not more than 1/2 of a length from the first surface to the second surface is provided on at least one of the first surface and the second surface, and an inclination angle of the depressed portion relative to the surface on which the depressed portion is provided is at least 10°.