The purpose of the present invention is to provide an inertial sensor having an angular velocity detection circuit configured so as to be synchronized with the resonance frequency of an angular velocity detection element, wherein a highly precise angle output having minimal integration error is realized in an integration circuit for angle sensing. The inertial sensor has an angular velocity detection element chip C1 having a mechanical structure for detecting angular velocity, and a signal processing LSI chip C2 as an angular velocity detection circuit for detecting angular velocity from the angular velocity detection element chip C1. The signal processing LSI chip C2 calculates an inclination angle by sampling a signal obtained from the angular velocity detection element chip C1 for a discrete time synchronized with the drive frequency of the angular velocity detection element chip C1.
