An inertial sensor, comprises a detection element detecting an amount of a physical quantity in a detection axis direction, a plurality of support members having flexibility and supporting nearly a center of the detection element, and a package substrate housing the detection element and the plurality of support members. In a case when an X-axis is defined as an extending direction of the plurality of support members, a Y-axis is perpendicular to the X-axis in a plane including the detection element, and a Z-axis is perpendicular to the X-axis and the Y-axis, one of load components in a direction of the Y-axis of the detection member applied to the plurality of support members is nearly equal to other among the plurality of support members, and one of load components in a direction of the Z-axis is nearly equal to the other among the plurality of support members.