To provide a metal-ceramic joined body having excellent fatigue resistance performance and long life even under severe use conditions and a tappet using the same.

The tappet 1 has a structure formed by joining a ceramic plate 4 via a brazing filler metal layer 3 to a metallic body 2. The metallic body 2 is composed of steel products formed with a quench hardened layer 20 on a surface layer part. The Vickers hardness of a main body portion 21 on an inner side exclusive of this quench hardened layer 20 is assured at Hv≥230. As a result, the trouble, such as the deformation of the brazing filler metal layer by the insufficiency of the rigidity of the metallic body 2, is eliminated and the joint strength and fatigue resistance performance are improved. The joint body having the long life and high reliability may be embodied even in the severe use conditions. In addition, the hardness of the brazing filler metal layer 3 may be formed to Hv≥80.