The performance of a permanent magnet magnetic refrigerator (PMMR) using gadolinium parallel plates is described. The configuration and operating parameters are described in detail. Experimental results are compared to simulations using an established twodimensional model of an active magnetic regenerator (AMR). In particular, the effect of geometric demagnetization in the regenerator is included in a simplified manner. The model and experimental data are in good agreement while the effect of demagnetization is seen to degrade the performance. It is concluded from the experiments that both thinner plates and channels are needed in order to obtain both temperature spans and cooling powers comparable to those obtained with packed spheres.