Liquid ejection chip and method for manufacturing liquid ejection chip

A liquid ejection chip having a first flow channel substrate and a second flow channel substrate bonded to each other by using an adhesive, the first flow channel substrate having an energy generation element configured to generate energy for ejecting liquid and a first flow channel configured to supply the liquid to the energy generation element, the second flow channel substrate having a second flow channel connecting to the first flow channel, wherein

• recess portions are formed at each of a wall surface of the first flow channel and a wall surface of the second flow channel,
• in terms of at least one of depth and width of the recess portions, the first flow channel substrate>the second flow channel substrate,
• at the wall surface of the second flow channel in the second flow channel substrate, the recess portions are formed in two or more sizes in terms of at least one of the depth and the width, and
• in the second flow channel, in terms of at least one of the depth and the width of the recess portions, the recess portions on a side of a first surface<the recess portions on a side of a second surface, where the first surface is a bond surface of the second flow channel substrate to the first flow channel substrate and the second surface is a surface of the second flow channel substrate which is opposite from the first surface.