Provided are a filter array, a spectral detector including the filter array, and a spectrometer employing the spectral detector. The filter array may have a multi-array structure including a plurality of filter arrays. The filter array may include a first filter array having a first structure in which a plurality of first filters with different transmittance spectrums are arranged, and a second filter array having a second structure in which a plurality of second filters with different transmittance spectrums are arranged, the second filter array being arranged to at least partially overlap the first filter array at a first position relative to the first filter array so that the multi-arrangement type filter array has a first set of absorbance characteristics. The second filter array may be configurable to be arranged to at least partially overlap the first filter array at a second position relative to the first filter array so that the multi-arrangement type filter array has a second set of absorbance characteristics different from the first set of absorbance characteristics.