This book provides a concise introduction to the complex subject of patent law as a major branch of intellectual property rights. It describes the application of patent law in order to obtain a patent for a scientist's invention. Comparison is also made between the patent laws of the four major jurisdictions under which most of the applications for patents are presently filed worldwide - China, Europe, Japan, and the USA. The systematic description of the patent process from draft to grant is aimed at facilitating teamwork between the inventor and the patent lawyer or intellectual property manager so that the invention is not only a great scientific achievement, but also a product of economic value for the applicant and the inventor.