A vibration state detection device includes an imaging device configured to image at least one driven element to be driven by a drive unit of a machine tool; and a vibration state analysis unit configured to calculate a parameter corresponding to vibration of the driven element, based on image data for each predetermined period of elapsed time acquired by the imaging device. The parameter includes at least a vibration frequency and a machine tool including the vibration state detection device. Accordingly, it is possible to reliably obtain a parameter corresponding to vibration caused by cutting, even if cutting oil, chips, or the like adheres to a tool of a machine tool, and it is possible to suppress vibration caused by cutting.