PURPOSE: To obtain a carbon dioxide absorbent having high activity and long life and convenient to handle, by mixing a powdery polyethylene resin and slaked lime while molding the resulting mixture at a specific temp. and, after boiling treatment, removing moisture adhered to the molded one before drying.

CONSTITUTION: 100pts.wt. of a powdery polyethylene resin and 50W200pts.wt. of slaked lime are mixed while the resulting mixture is molded at a temp. T in a range of (Tm+30°C≥T>Tm-15°C) with respect to the m.p. Tm of the polyethylene resin and, subsequently, the molded product is subjected to boiling treatment and, after moisture adhered to the molded product is removed, dried at 50W80°C. The shape of this molded product is set to a pellet or tablet form and the void ratio thereof is set to 10W50%. Carbon dioxide absorbent thus obtained has high activity and long life and is convenient to handle.