PROBLEM TO BE SOLVED: To provide a metalized substrate having comparatively small degradation to joining strength before heat treatment at relatively high temperature even after the heat-treatment, and a joint body of aluminum with ceramics.SOLUTION: In the metalized substrate, a metal film including at least Ag, Ti and Al is formed on the principal surface of a ceramic substrate, and a connecting layer including 10 mass% or more of each AL and O and 50 mass% or more of the total amount of Al and O is formed in a boundary portion between the metal film and the ceramic substrate.