A method for producing acetic acid, the method comprising: a first absorption step of: feeding, to an absorption column, at least a portion of offgases formed in an acetic acid production process; bringing the fed offgas into contact with a first absorbent in the absorption column to allow the first absorbent to absorb an iodine compound from the offgas, the first absorbent including at least one liquid selected from the group consisting of: C2 or higher alcohols; esters of C3 or higher carboxylic acids; esters between carboxylic acids and C2 or higher alcohols; ethers; ketones; water; and basic aqueous solutions; and whereby separating into: a first gas having a lower iodine compound concentration as compared with the offgas; and a first solution containing the iodine compound and the first absorbent; and a second absorption step of: bringing the first gas into contact with a second absorbent in the absorption column or in another absorption column to allow the second absorbent to absorb an iodine compound from the first gas, the second absorbent differing in composition from the first absorbent and including at least one liquid selected from the group consisting of: C2 or higher alcohols; esters of C3 or higher carboxylic acids; esters between carboxylic acids and C2 or higher alcohols; ethers; ketones; water; basic aqueous solutions; and acetic acid; and whereby separating into: a second gas having a lower iodine compound concentration as compared with the first gas; and a second solution containing the iodine compound and the second absorbent. feeding, to an absorption column, at least a portion of offgases formed in an acetic acid production process; bringing the fed offgas into contact with a first absorbent in the absorption column to allow the first absorbent to absorb an iodine compound from the offgas, the first absorbent including at least one liquid selected from the group consisting of: C2 or higher alcohols; esters of C3 or higher carboxylic acids; esters between carboxylic acids and C2 or higher alcohols; ethers; ketones; water; and basic aqueous solutions; and C2 or higher alcohols; esters of C3 or higher carboxylic acids; esters between carboxylic acids and C2 or higher alcohols; ethers; ketones; water; and basic aqueous solutions; and whereby separating into: a first gas having a lower iodine compound concentration as compared with the offgas; and a first solution containing the iodine compound and the first absorbent; and a first gas having a lower iodine compound concentration as compared with the offgas; and a first solution containing the iodine compound and the first absorbent; and a second absorption step of: bringing the first gas into contact with a second absorbent in the absorption column or in another absorption column to allow the second absorbent to absorb an iodine compound from the first gas, the second absorbent differing in composition from the first absorbent and including at least one liquid selected from the group consisting of: C2 or higher alcohols; esters of C3 or higher carboxylic acids; esters between carboxylic acids and C2 or higher alcohols; ethers; ketones; water; basic aqueous solutions; and acetic acid; and C2 or higher alcohols; esters of C3 or higher carboxylic acids; esters between carboxylic acids and C2 or higher alcohols; ethers; ketones; water; basic aqueous solutions; and acetic acid; and whereby separating into: a second gas having a lower iodine compound concentration as compared with the first gas; and a second solution containing the iodine compound and the second absorbent. a second gas having a lower iodine compound concentration as compared with the first gas; and a second solution containing the iodine compound and the second absorbent. <EOS>