A method of manufacturing packing includes: determining types of a gas and a liquid which are brought into gas-liquid contact and a main plate to be used; calculating a relationship between a contact angle and a liquid film length ratio; determining the arrangement (intervals) of a rib; determining rib conditions; calculating the minimum value of the flow direction length of the rib satisfying the contact angle and a strength requirement; confirming whether or not a liquid film length is greater than the minimum value; and determining the flow direction length of the rib within a range from the minimum value to the liquid film length.