An infrared imaging microscope, particularly of the type used to carry out FT-IR measurement, including a detector in the form of a relatively small detector array of individual detector elements. The outputs of the detector elements are fed in parallel to an electronic circuit for processing. The relatively small array allows the outputs to be processed without need for multiplexing thereby avoiding reduction in signal-to-noise. The detector array may substantially range from about 3 to about 100 detector elements, and is preferably in a range from about 16 to about 64 detector elements.