To provide an apparatus and a method for feeding a fluid, which are free from the troubles that a solidified reaction product having adhered and grown in the periphery of a fluid feed inlet opened in a reaction vessel of an esterification apparatus or in the circulation pipeline clogs the fluid feed inlet to stop continuous feed of a fluid.

In a fluid feed apparatus having a fluid feed pipeline 5 for feeding a diol or a slurry of a diol and a dicarboxylic acid, which is connected with a reaction vessel 1 of an esterification reaction apparatus or a circulation pipeline 6 for the reaction product, the connecting part of the fluid feed pipeline 5 is provided with a switch means for switching a fluid feed inlet 11 opened at the reaction vessel 1 or the circulation pipeline 6 and a removal means (a valve rod 11) for removing adhered substances to be formed at the fluid feed inlet 11.