The inductively coupled plasma (ICP) reactive ion etching of Pyrex glass was carried out using SF6/Ar plasmas. The etch rate and surface and sidewall smoothnesses were investigated systematically through their dependence on bias voltage, ICP power, pressure, flow rate, and cathode temperature. Near vertical sidewalls and smooth etched surfaces were obtained by optimized etching parameters. The maximum etch rate, 0.65 μm/min, was achieved at a pressure of 5 mTorr, a bias of 720 V, and an ICP power of 2500 W. Microfluidic devices with various sizes on Pyrex glass have been designed and fabricated. Two types of electrokinetic flow patterns, which are extensional and rotational flows under different biases, have been successfully demonstrated with five cross microfluidic devices.