Process for producing (meth)acrylic acids and process for distilling the same

A process for producing (meth)acrylic acids including stopping and starting operations of a distillation column used therefor, comprising:

• stopping the operation of the distillation column, interrupting the heating of a reboiler attached thereto, and then rapidly cooling the reboiler by reducing the bottom temperature of the distillation column to not more than 50° C. within a period of 150 to 300 minutes;
• and/or
• starting the operation of the distillation column for production of the (meth)acrylic acids, heating an inner wall surface of the distillation column to a temperature higher than a condensation temperature of the (meth)acrylic acids, and starting the operation of the distillation column under the heated condition wherein in the stopping and starting operations of the distillation column, solids derived from the (meth)acrylic acids, which are adhered onto surface of a handling device including conduits, are washed out and removed using a washing agent containing a volatile base substance.