Four sensor units (SUA1 to SUA4) are disposed symmetrically about a point, on both top and bottom and left and right centering around one point of a support (15e). Furthermore, four sensor units (SUA1 to SUA4) are designed so that all the components are fully in tuning-fork structure. Drive frames (5, 5) of the sensor units (SUA1, SUA2) disposed adjacent to each other in a first direction (Y) are vibrated in mutually inverted phases, and drive frames of the other sensor units (SUA3, SUA4) disposed adjacent to each other in a second direction (X) are vibrated in mutually inverted phases as well. Moreover, the drive frames of the sensor units (SUA1, SUA2) and the drive frames of the other sensor units (SUA3, SUA4) are operated in synchronization in the state in which phases are shifted by 90 degrees. Whereby, it is possible to reduce or prevent vibration coupling in the driving direction and in the detection direction, and the leakage (loss) of excitation energy and Coriolis force. Thereby, performance of an inertial sensor is improved.