The wire rope flaw detector includes: buffer members provided on both sides of the probe in an axial direction of the wire rope and between a connecting member and the probe. The connecting member is configured to connect a first and a second position regulation mechanism with each other, and is configured to guide the wire rope. The buffer members are made of a material satisfying conditions that, during running of the wire rope, a vibration frequency of the buffer members becomes lower than the vibration frequency of vibration generated by the first and the second position regulation mechanism, and have an inherent vibration frequency larger than the vibration frequency of the vibration having a largest amplitude among vibration components of the wire rope. The adjustment jig is used at an initial adjustment so that a guide groove of the probe is supported by the position regulation mechanisms without contact.