(57) Abstract: A device for measuring the frequency and / or amplitude of the vibrating structure, this apparatus is particularly suitable for applications such as measuring the acceleration and angular velocity, the movable member 2 which can be vibrated It is provided. By two positions the position sensor pairs consisting of sensors 10 and 11, and so as to measure the displacement of the movable member 2, which two position sensors are their two position sensors in the half-wave period of the oscillation one of the detected value of each is are arranged so as to exceed the other and / or below. Further, by the comparator, the comparison together two detection values ​​of the respective position sensors 10 and 11, from the comparison result, and to be required a threshold value U _s in half-wave period of the vibration. Further, the time measuring means, so as to obtain the period length of the period detected value is lower than the period and / or exceeds the threshold value U _s of one position sensor of said two position sensors 10, 11 It has to. Further, the position sensor 10 and 11, for example constituted by a capacitor, the plurality of electrodes may be disposed with a step difference. With the above, even when the movable member 2 has generated the movement displacement parallel, whereby it is possible to measure the vibration amplitude without being affected at all, therefore, impaired the measurement results of the oscillation amplitude by such displacement that there is no.