To provide a low cost and highly reliable screw fixture, a resonator device with a characteristic adjusting function having the screw fixture, and a characteristic adjusting method of a filter including the resonator device, an oscillator, a communication device, and the resonator device.

A recess d recessed in the thickness direction is formed in the vicinity of a shaft of a locking nut 2 of a characteristic adjusting screw 1. A projected part p engaged with the recess d of the screw locking nut 2 is arranged to a spring washer 3. The spring washer 3 is sandwiched between a panel 4 and the screw locking nut 2, and the characteristic adjusting screw 1 is rotated under a proper load. After adjusting a characteristic, the screw locking nut 2 is fastened until the spring washer 3 is completely collapsed, and these members are locked.