A force sensor has an input part, a base part, an intermediate part and a sensor element. The external force to be sensed is applied to the input part. The input part transmits the external force to the base part via the intermediate part. The base part is fixed to a frame of reference and exerts a reaction force on the input part via the intermediate part. The intermediate part deforms as a result of the external force and the reaction force. The deformation of the intermediate part causes the input part to change its position or orientation relative to the base part. The sensor element senses this change and supplies an output signal representative of the change.