This book discusses the work aimed to develop plastic millimeter-wave components, including waveguides, tunable filters, phase shifters and antennas, toward the low-cost, batch fabrication for integrated systems for applications such as all-weather automotive and airplane landing radars. The key micromachining processes developed in this work include micro hot embossing, electroplating, polishing and bonding and as a proof of concept demonstration, micro injection molding of a plastic microneedle is also presented.