With short wavelength light sources, VLSI chips with less than 0.5μm line width can be produced. In such case, alignment accuracy must be 0.1μm or less. Mechanical positioning accuracies of the stages, such as a wafer stage or a mask alignment stage, govern the total overlay accuracy. This report presents a mechanical improvement for the mask alignment stage, such as improvement in X,Y axes motion accuracy and realizing Z and tilt motion controls. A prototype compact and high precision alignment stage has been manufactured. In order to improve the X,Y motion accuracy, the stage has friction drive mechanisms and has a measuring method with analog/digital conversion of linear scale signals. In the experimental results obtained from the X,Y stage, less than 0.025μm motion resolution has been obtained.' No backlash, no stick-slip, and no hysteresis have been observed.