The presented latching-type 2 by 2 and 1 by 4 fiber-optic switches are based on full wafer micromachining of silicon wafers using anisotropic wet etching in KOH. Bulk micromachining allows the low-cost batch fabrication of structures with very high precision suitable for fiber alignment. The optical fiber switches consist of two thermally driven silicon actuators, a coupled U-shaped cantilever via thin flexible silicon beams and a stiff platform prevents angular displacement of the fibers. Switches have been fabricated with high yield, high mechanical stability, and good optical properties. Using standard single- mode fibers, the switches exhibit a crosstalk of < - 60 dB. Insertion losses below 1 dB and about 1 dB are achievable for 1 by 4 and 2 by 2 switches, respectively. A power below 0.6 W and 1.0 W for the 2 by 2 and 1 by 4 micromechanical fiber switch is needed during the switching time. Bistable 1 by 2 optical fiber switches have been tested for more than 1 X 106 switching cycles without any failure and after more than one year at room conditions they do not show any degeneration of optical properties and switching behavior.