The technological break-through introduced by the advent of microsensors, microsystems and MEMS in the last decade has enabled the widespread diffusion of sensing devices in a huge number of application fields, form consumer electronics and mobile devices to automotive and domotics, becoming one of the pillars of the Internet of Things (IoT). This seminar touches the most important aspects associated with the design and implementation of integrated microsystems, from MEMS operating principle and fabrication technology to integration with electronics and packaging. The most critical aspects in the design of MEMS devices and read-put electronics are also discussed, with the help of a few actual examples.