  We characterized spatially resolved spectral phase interferometry with an
isolated attosecond pulse (IAP). The measured spatial-spectral interferogram
and spectral interference fringe visibility show a high degree of IAPs spatial
and spectral coherences. In addition, the characterized spectral-delay
interferogram shows periodic temporal oscillations over the full IAP continuous
spectrum, which indicates high temporal coherence. The IAP coherence over broad
continuous spectral region holds potential for realizing the time-resolved IAP
phase-based spectroscopy, which will contribute to exploring spatiotemporal
dispersive electronic wave dynamics in the future.
