Production process of (meth) acrylic acid.

A process for the production of a compound of (meth) acrylic acid, comprising the reaction of a raw material mixed gas by oxidation stage is catalytic in an oxidation reactor to produce (meth) acrolein or (meth) acrylic , wherein the temperature of the raw material mixed gas introduced into the oxidation reactor is maintained to be from 5 to above the dew point temperature of the raw material mixed gas of 25 ° C.