To provide a crystal oscillator and a crystal-controlled oscillator, having a space widened in a package while miniaturizing the package, a sound configuration as well, and allowing to have airtightness.

In this crystal oscillator, first and second frame walls 1b, 1c of ceramic are formed around a ceramic substrate 1a on which a crystal piece 2 is mounted, the substrate 1a, and the first and second frame walls 1b, 1c are stacked and baked, moreover, the first frame wall 1b is thinner than the second frame wall 1c, and a lid 4 is provided on the second frame wall 1c and sealed. The crystal-controlled oscillator uses this crystal oscillator.