We present the first mid-infrared spectra of two cool white dwarfs obtained with the Spitzer Space Telescope. We also present 3:5Y8 m photometry for 19 cool white dwarfs with 5000 K TeA 9000 K. We perform a detailed model atmosphere analysis of these white dwarfs by fitting their UBVRIJHK and Spitzer photometry with state-ofthe-art model atmospheres, and demonstrate that the optical and infrare...