A very high resolution (R = 1.2 x 105) mid-infrared spectrograph for astronomical observations is proposed. The spectrograph will be a liquid helium cooled, double-pass, echelle using a 40 cm long grating. It will be able to resolve lines with 2.5 km s-1 Doppler width and will have a noise-equivalent line flux of ~ 4 x 10-14 erg s-1 cm-2 (1. in 1 second), allowing high signal-to-noise observations of many young stars embedded in molecular clouds. The instrument will be used primarily for studies of interstellar molecules. Very high resolution and high sensitivity observations are necessary for infrared observations of molecular clouds, especially the regions around young stars.
