For the purpose of obtaining an accurate performance of a disk friction pump rotor, theories in a previous report are compared with experiments. The laminar flow theory with modification in the inlet region agrees well with the exprimental results when a disk clearance of the rotor is narrow. The outer end effect of disks is discussed. On the basis of these results, formulae are made of the performances of the disk friction pump rotor, and optimum disk clearance and optimum radius of inner periphery of the rotor are given. Furthermore, whether a flow regime in the rotor is laminar or turbulent is experimentally analyzed. In the experiments, it has been confirmed that the flow regime is always laminar except for a small region near the inner and the outer periphery, and that two types of vortex rows can be observed in compliance with the flow rate change.