Liquid ejection head inspection method, liquid ejection head inspection apparatus, and ejection element substrate

An inspection apparatus for inspecting a liquid ejection head including an ejection element substrate which has a substrate, a heat generation portion having an electrothermal converter provided on a first surface of the substrate, a protective film covering the electrothermal converter, and an organic layer covering the electrothermal converter and the protective film, the ejection element substrate being capable of ejecting liquid in a flow channel formed between the organic layer and the protective film through an ejection port formed in the organic layer by using heat generated at the heat generation portion, the inspection apparatus comprising:

• a resistance value measurement unit configured to acquire, as a first measurement result, an electrical resistance value of the electrothermal converter;
• a film thickness measurement unit configured to acquire, as a second measurement result, a film thickness of the protective film at a film thickness measurement portion of the ejection element substrate where the protective film is exposed;
• and
• an obtainment unit configured to obtain information on ejection energy needed to eject liquid through the ejection port based on the first measurement result and the second measurement result.