The invention relates to a vibrating wire sensor (20, 30, 40 and 50) having a vibrating wire (21, 31, 41 and 51), which is tensioned accordingly differently under measurement conditions of a current factor to be detected, and having an exciter arrangement for exciting the vibrating wire (21, 31, 41 and 51) in the range of the respective natural frequency thereof, wherein the exciter arrangement has at least one exciter layer (22, 32, 42 and 52) provided on a longitudinal portion of the vibrating wire (21, 31, 41 and 51), having a piezoelectric activation layer (33, 46 and 54), which has a different length depending on the activation state, and thus creates a correspondingly different vibration position of the vibrating wire (21, 31, 41 and 51). A vibrating wire sensor can thus be designed to be more robust, wherein the power consumption is additionally considerably less. The invention further relates to a vibrating wire having an exciter layer (22, 32, 42 and 52), which has a piezoelectric activation layer.