We present several types of translatory MOEMS actuators developed for fast optical-path-length modulation [e.g., in confocal microscopes or Fourier-transform infrared (FTIR) spectrometers] and their application on miniaturized FTIR spectrometers capable of performing time-resolved measurements from the near infrared to the mid infrared. The MOEMS devices are manufactured in a complementary metal oxide semi conductor compatible silicon-on-insulator process. They are electrostatically resonant, driven using in-plane comb drives. A first translatory 5-kHz MOEMS device is used in a first prototype of a miniaturized MOEMS-based FTIR spectrometer where the MOEMS actuator replaces the macroscopic mirror drive, enabling a miniaturized, robust, and low-cost FTIR system. The mirror plate of is suspended by bending springs. Due to the resonant operation, a stroke can be achieved with low voltages at an ambient pressure below . Consequently, this yields a spectral resolution of and an acquisition time of per spectrum. In addition, we present a novel MOEMS device with an increased mirror aperture of and pantograph-like mirror suspension enabling up to a stroke. This device is specifically optimized for miniaturized FTIR spectrometers to enable an improved spectral resolution of and a signal-to-noise ratio of .