Motion sensor, and method of manufacturing motion sensor

A sensor device 1 includes: a silicon substrate 10; a first electrode 11 provided at an active surface 10a side of the silicon substrate 10; an external connection terminal 12 provided at the active surface 10a side so as to be electrically connected to the first electrode 11; a stress relief layer 15 provided between the silicon substrate 10 and the external connection terminal 12; and a vibrating gyro element 20 as a sensor element including a extraction electrode 29. The vibrating gyro element 20 is held to the silicon substrate 10 by connection between the extraction electrode 29 and the external connection terminal 12.