ISOCAM observations of the centre of M31

We present ISOCAM images and CVF observations of the centre of the Andromed a Galaxy. The images were taken in the LW1, LW2, LW3 and LW6 filters. They show an elliptical contribution of the stars and the spatial distribution o f dust. The dust distribution follows a spiral structure identical to the d istribution of absorption at optical wavelengths. The spectrum of the dust as seen from the CVF observations shows only one broad emission band at 11. 3 mum while other PAH features at 6.2, 7.7 and 8.6 mum are absent or very f aint. This seems to correspond to infrared emission of combinations of neut ral polycyclic aromatic hydrocarbons.