A spectrometer recognizes a measurement target on the basis of the spectral data set of observed light detected by a spectral sensor capable of measuring wavelength information and light intensity information. The spectrometer is provided with a spectral data processor. Spectral data sets are detected at two different positions by the spectral sensor, and the processor subtracts a first spectral data set from a second spectral data set, or divides the first spectral data set by the second spectral data set to calculate one phase correlation spectral data set, which is correlated to the spectral data sets at the two different positions. The processor simultaneously identifies the measurement target corresponding to the two different positions on the basis of the correlation spectral data set.