A method for rectification includes steps of supplying raw materials to a rectifying column from a raw material feed pipe; returning a refluent fluid from a refluxing pipe to the column; leading a hold-up liquid from a bottom tank having a higher surface to a bottom tank having a lower surface of a liquid in a bottom portion of the column; heating the hold-up in each of bottom tanks; exchanging heat by bringing a vapor produced by heating the bottoms into counter-current contact with the reluent liquid returned to the rectifying column on plates arranged in the rectifying column, taking out a vapor from the top of the rectifying column, and taking out bottoms from the bottom tank. An apparatus for rectification includes a rectifying column having a raw material feed pipe, an offtake pipe for taking out the vapor, a reflux pipe for returning the refluent liquid to the inside of the column in the upper portion of the rectifying column and plates for exchanging heat by bringing the vapor into contact with the refluent liquid. The bottom portion is divided into at least two bottom tanks having surfaces of liquid different in height, in the bottom portion of rectifying column. The bottoms in each of the bottom tanks are heated and an offtake pipe takes out the bottoms.