A manufacturing method of an absorption cell includes preparing a first absorption layer formed of a mixture of a first absorbent and a second absorbent having a higher density than the first absorbent; coating the surface of the first absorption layer with a protective layer formed of a low-carbonizing point material and the second absorbent so as to prevent generation of dust particles from the first absorption layer; and removing the low-carbonizing point material from the protective layer so as to form a second absorption layer including a plurality of pore parts through which a fluid flows to the first absorption layer.