To prevent improper oscillation.

The oscillator is provided with a board 1, a vibrator 2 supported to one side of the board 1, a cover 3 covering the vibrator 2 and a control element 4 that is mounted to the other side of the board 1 and controls the vibrator 2, a 1st electrode 6 is provided to one side of the board 1 and connected electrically to the vibrator 2, a 2nd electrode 8 is provided to the other side of the board 1 opposite to the 1st electrode 6 and connected electrically to the control element 4. Then a recess 9 is provided to at least one side and the other side of the board 1 on which the 1st and 2nd electrodes 6, 8 are provided and the 1st electrode 6 or the 2nd electrode 8 is provided in the recess 9.