Abstract: In a piezoelectric resonator container having a cylindrical case, one end of which is an open end, and a stem for sealing the open end of the case, an outer peripheral face of the stem and an inner peripheral face of the case have a nearly elliptical shape or an elliptical shape, respectively. A pressure allowance when pressing the stem into the open end of the case monotonically increases from a major axis portion of the case toward a minor axis portion. Therefore, since the pressure allowance is large at minor axis portions where vertical stress tends to decrease and the pressure allowance is small at major axis portions where tensile stress tends to increase, incomplete gas-tightness due to inadequate sealing or breaking of the case does not occur. This provides a piezoelectric resonator container in which incomplete gas-tightness is not caused, even if an elliptical or a nearly elliptical case is used, and a piezoelectric resonator piece does not come into contact with the inner periphery of the case.