Linear focal Cherenkov ring camera (LFC-Camera) has been developed for single shot measurement of longitudinal phase space distribution of quasi-relativistic electron beam, where the electron's velocity still depends on its energy. The LFC-camera employs velocity dependence of opening angle of Cherenkov light produced by electron beam to observe its energy (momentum) distribution. Since the Cherenkov light contains the time information if the radiator medium is thin enough, we can get the longitudinal phase space distribution measuring both time and energy spectra simultaneously using a streak camera. We employ a thin silica aerogel with water-free hydrophobic treatment as Cherenkov radiator. We have evaluated characteristics of the silica aerogel radiator, and demonstration of the LFC-camera at a beam diagnosis section of t-ATCS is being proceeded.