- M/A-COM
- Macronix (MX)
- Magnecraft & Struthers-Dunn
- Magnetek
- Major League Electronics
- Mallory
- Manhattan/CDT
- Marmah Magnetics
- Marquardt Switches
- Matrix Orbital Corp.
- Matsushita Electronic Components
- Maurey Instrument Corp.
- Maxim
- Maxitech Elektronik AB
- McKenzie Socket Division
- Meiden Quartz
- Melcher
- Melcor
- Membrane Switch Technologies, Inc.
- Menlo Industries
- Mercury Crystal Products (MEC)
- Meritec
- Merrimac Industries, Inc.
- Metelics
- Methode
- MF Electronics Corp.
- Micrel
- Microchip
- MicroClock, Inc.
- MicroDisplay Corp.
- Micro Electronics Corp.
- Microelectronics Modules Corp. (MMC)
- Micro Fasteners
- Microlab/FXR
- Micro Linear
- Micro Mo Electronics
- Micronas Semiconductor
- Micronel U.S.
- Micro Networks
- Micron Guard, Inc.
- Micron Technology
- Micro-Ohm
- Microphase Corp.
- Micro Plastics, Inc.
- Microsemi
- Microwave Components Laboratories
- Microwave Dynamics
- Microwave Filter Co.
- Microwave Power, Inc.
- Microwave Solutions, Inc.
- Micrys, Inc.
- Midcom
- Million Spot Ltd.
- Mill-Max
- Mini Circuits
- miniReel
- MIPS Processors
- Mitel
- Mitsubishi
- Mixed Signal Integration
- Modular Power Systems
- Modulohm A/S
- Molex
- Mosel Vitelic
- Motorola
- Mpulse Microwave
- M.S. Kennedy (MSK)
- MTI-Milliren
- M-tron Industries, Inc.
- Mueller Electric Co.
- Mupac Electronic Packaging
- Murata North America
- Murata Japan
- Music Semiconductors
- MX-COM, Inc.
