Channel electron multipliers are vacuum-electron devices for detection of charged particles and energetic photons. Several manufacturing technologies for microelectronics and microelectromechanical systems hold significant promise for the development of a new generation of silicon-based channel electron multipliers with greater capabilities and broader applications than conventional glass-based ones. This paper describes several approaches to microfabrication of such devices using surface and bulk micromachining techniques. Results are presented for fully micromachined channel electron multipliers with signal gains in the range of 10-10.