To provide a force detection device not utilizing a capacity change.

This force detection device 1 is equipped with a hard thin magnetic membrane 6 arranged on a substrate 4. An MR thin membrane 7 is arranged on the substrate 4 so that the MR thin membrane 7 is under the influence of a magnetic field generated from the hard thin magnetic membrane 6. A cantilever member 3 is mounted so as to vibrate corresponding to the vibration force. The magnetic field functioning on the MR thin membrane 7 is vibrated by vibration of the cantilever member 3, and the electric characteristic of the MR thin membrane 7 is vibrated and changed by the vibration of the magnetic field. The vibration change of the electric characteristic corresponds to the vibration of the cantilever member 3.