2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/228221We can solve the Wheeler-DeWitt equation of the small universe enough to metric becomes diagonal and take a Gaussian normal coordinate. Our previous works are concerning to this paper. In this paper, we only write how to solve the Wheeler-DeWitt equation of such universe. Our motivation is simple, that is to solve the Wheeler-DeWitt equation. Even if the Wheeler-DeWitt equation is solved, quantum gravity does not complete yet. However, this work may be one of the first step to quantum gravity.6 page, no figureGeneral Relativity and Quantum Cosmologytext