PROBLEM TO BE SOLVED: To provide an oven controlled crystal oscillator in which the frequency-temperature characteristics can be improved, by reducing the thermal resistance between a heat source component and thermistor and a crystal blank.SOLUTION: An oven controlled crystal oscillator includes a heat source component 23, a thermistor 22, and a pin type crystal oscillator 25. The crystal oscillator 25 includes an encased crystal blank 251, a lead 252 led out from the electrode of the crystal blank, and a crystal base 253 having a convex surface on the crystal blank side, and a concave surface on the opposite side. The recess of the crystal base 253 is filled with a glass portion 255 for fixing the crystal lead 252 to the crystal base 253, and a heat-conducting portion 256 formed sequentially.
