To miniaturize a fractional distillation apparatus by uniting a heat exchanger and an evaporation chamber and widening a heat transfer area by providing a conical shield plate in the evaporation chamber to accelerate evaporation to make it efficient.

In the fractional distillation apparatus, a heat exchange chamber (2) is provided to the side surface of the evaporation chamber (1). The conical shield plate (4) is provided in the evaporation chamber (1) to make evaporation efficient.