Patent ID: 8449783

Claim:
A method of manufacturing a liquid ejection head substrate including a step of forming a liquid supply port extending from a second surface to a first surface of a silicon substrate, the first surface and the second surface being oppositely disposed, the method comprising: a step of forming a wiring pattern on the first surface; a step of forming an etching mask layer on the second surface; a mark forming step of forming a positioning reference mark on the etching mask layer by means of a laser from above the etching mask layer on the second surface; a laser machining step of forming an opening pattern groove running through the etching mask layer on the second surface and having a bottom in the inside of the silicon substrate, using the positioning reference mark; and a step of forming a liquid supply port running through the silicon substrate by etching the silicon substrate from the opening pattern groove to the first surface by means of crystal anisotropic etching.