LISA is the low resolution imaging spectrometer channel for SPICA. the proposed spectral-photometric-IR camera for the joint US and German stratospheric far IR observatory SOFIA. LISA will cover a spectral range from 40 micrometers to 220 micrometers at a spectral resolution (lambda) /(Delta) (lambda) approximately 22. It will record simultaneously individual diffraction limited spectra from several tens to several hundreds spatial positions of a rectangular field of view on the sky. A novel technical and optical solution will be presented for such an approach together with a brief discussion on the expected performance and possible astronomical applications.