In recent years, computer and associated software technology has become of increasing importance in any spectroscopy laboratory. A variety of computer techniques are being applied not only to numerical analyses of spectra but also to automatic data collection for releasing the spectroscopist from tedious and time-consuming work. However, it should be noted that the computer also demonstrates its tremendous power in increasing the reliability of data which will be endurable for further analysis. This article presents the current status on computer applications particularly to numerical data handling for accomplishing reliable spectroscopic measurements, which covers main categories of waveform processing such as Fourier transformation, digital filtering, deconvolution and curve decomposition.