各国对专利申请的审查有不同的要求，基本上实行两种不同的制度。有的国家实行形式审查制，即只审查专利申请书的形式是否符合法律的要求，而不审查该项发明是否符合新颖性等实质性条件。有些国家则实行实质审查制，即不仅审查申请书的形式，而且对发明是否具备新颖性、先进性和实用性等条件进行实质性的审查，只有具备上述专利条件的发明，才授予专利权。中国和世界上大多数国家采用实质审查制。
Different countries have different requirements for the examination of patent applications and basically implement two different systems. Some countries implement the form examination system, that is, only examine whether the form of the patent application conforms to the requirements of the law, and not examine whether the invention conforms to substantive conditions such as novelty. In some countries, a substantive examination system is adopted, that is, not only the form of application is examined, but also the conditions for novelty, advancement and practicability of the invention are examined in substance. China and most countries in the world adopt the substantive review system.