微电子学（Microelectronics）是研究在固体（主要是半导体）材料上构成的微小化电路，子系统及系统的电子学分支。微电子学作为电子学的一门分支学科，主要是研究电子或离子在固体材料中的运动规律及其应用，并利用它实现信号处理功能的学科。微电子学是以实现电路和系统的集成为目的的。微电子学中实现的电路和系统又成为集成电路和集成系统，是微小化的；在微电子学中的空间尺寸通常是以微米（μm，1μm=m）和纳米（nm，1nm=m）为单位的。

Microelectronics is a subfield of electronics. As the name suggests, microelectronics relates to the study and manufacture (or microfabrication) of very small electronic designs and components. Usually, but not always, this means micrometre-scale or smaller. These devices are typically made from semiconductor materials. Many components of normal electronic design are available in a microelectronic equivalent. These include transistors, capacitors, inductors, resistors, diodes and (naturally) insulators and conductors can all be found in microelectronic devices. Unique wiring techniques such as wire bonding are also often used in microelectronics because of the unusually small size of the components, leads and pads. This technique requires specialized equipment and is expensive.