The influence of one-sided anode (asymmetrical electrode configuration) on the performance of an experimental disk-MHD generator with small thermal input was examined experimentally and numerically. In MHD power generation experiments, the performance of a disk MHD generator with one-sided anode is confirmed to be comparable to that of a disk MHD generator with both-sided anode (symmetrical electrode configuration). From the results of r-z numerical simulations, the plasma properties in the disk MHD generator with one-sided anode are asymmetric in the z-direction near the downstream edge of anode. However, the r-z distributions of the fluid properties and performance in the disk MHD generator with one-sided anode are almost the same as those in a disk MHD generator with both-sided anode. These facts indicate that the asymmetrical electrode configuration hardly influences the performance of the disk MHD generator.