Abstract: Light from a light emitter is made into a linear beam extending in parallel with a direction of movement of a detection object and the beam is cast on the detection object. A linear reflected beam that is the linear beam reflected from the detection object is made incident on a light receiver. Thus first output waveform signals from the light receiver at a first time point and second output waveform signals from the light receiver at a second time point are stored into a storage unit. A moving amount detecting unit detects an amount of shift between the first output waveform signals and the second output waveform signals and calculates a moving amount of the detection object on basis of the amount of shift. Thus an optical moving amount detecting device is provided that is capable of accurately measuring a moving amount of a detection object having smooth surfaces.