A distance measuring device includes first and second cameras, first and second Fourier pattern data generating sections, a pattern processing section, and a distance measuring section. The two cameras are spaced apart from each other by a predetermined distance. The first Fourier pattern data generating section generates first two-dimensional Fourier pattern data by performing two-dimensional discrete Fourier transform for image data picked up by the first camera as first pattern data. The second Fourier pattern data generating section generates second Fourier two-dimensional pattern data by performing two-dimensional discrete Fourier transform for image data picked up by the second camera as second pattern data. The pattern processing section synthesizes the first and second Fourier two-dimensional pattern data, and performs either two-dimensional discrete Fourier transform or two-dimensional discrete inverse Fourier transform for the synthesized data. The distance measuring section obtains a correlation peak in a range excluding a portion near a reference position in a correlation component area appearing in the synthesized Fourier two-dimensional pattern data, and measures the distance to a target on the basis of the distance from a reference position in the correlation component area to the position of the correlation peak.