2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/50233The classical first law of thermodynamics for a Kerr-Newman black hole (KNBH) is generalized to a law in quantum form on the event horizon. Then four quantum conservation laws on the KNBH equilibrium radiation process are derived. The Bekenstein-Hawking relation ${\cal{S}}={\cal{A}}/4$ is exactly established. It can be inferred that the classical entropy of black hole arises from the quantum entropy of field quanta or quasi-particles inside the hole.7 pages, no figure, Revtex in 12ptHigh Energy Physics - Theorytext