According to the embodiment, there is provided a blade vibration measuring apparatus, having, a contactless displacement 5 sensor which outputs a displacement measurement signal as measuring a displacement of a turbine moving blade in a rotation axis direction, a blade top position identifying device which outputs a blade top position identification signal to identify a top position based on a distance between the contactless displacement sensor 10 and the top position of the turbine moving blade as receiving the displacement measurement signal output from the contactless displacement sensor, and a blade vibration calculating device which calculates vibration amplitude and a vibration frequency of the turbine moving blade based on temporal variation of the distance 15 between the contactless displacement sensor and the top position of the turbine moving blade as receiving the blade top position identification signal output from the blade top position identifying device.