To provide a method for reading out symbol information and a device for reading out symbol information which are able to prevent a decline in decoding reliability by reducing noise caused by a quantized error, localized contaminations or the like. The method for reading out symbol information may comprise a process in which the image data, obtained by imaging the symbol information such as bar codes and the like, are converted to corrected image data having zero angle of inclination; a smoothing process in which the corrected image data are smoothed; and a column specifying process in which breakpoints of said symbol information column are specified by computing the total sum in the row direction on the smoothed corrected image data.