The present invention provides an apparatus for handling an easily polymerizable compound such as (meth)acrylic acid which includes a tubular member that is furnished to a side wall of the apparatus and opened to the inside of the apparatus, specifically, for example, an apparatus and a method which effectively inhibit the polymerization of (meth)acrylic acid in a distillation column for (meth)acrylic acid wherein the distillation column has such as an inlet or outlet of gas or liquid, a manhole, or a tube into which an instrument is inserted. The tubular member (e.g. an inlet or outlet, a manhole, a tube into which an instrument is inserted) is set so as to have a downward gradient (&agr;) in the range of 3° to 70° toward the inside of the apparatus.