A distillation apparatus of the present invention includes high-pressure column 1 corresponding to a region above a heat exchanging section located at a lowermost part of a region including a trayed section or a packed bed section, which is used as a rectifying section; and low-pressure column 2 that is located above as seen from high-pressure column 1, which integrates a region including a trayed section or a packed bed section which is used as a stripping section, with rectifying section corresponding portion 2g that corresponds to a region locating below the heat exchanging section located at the lowermost part in the rectifying section. Rectifying section corresponding portion 2g is located on top 2c of the stripping section in low-pressure column 2 so that rectifying section corresponding portion 2g continues to the stripping section.