A method for manufacturing a filler comprises: a main condition determination step (Step 1) for determining types of gas and liquid to undergo gas-liquid contact and a main plate (11) to be used; a numerical analysis step (Step 2) for calculating the relationship between a contact angle (θs) and liquid film length ratio (Lw/Lt); a rib disposition determination step (Step 3) for determining disposition (spacing) of ribs (12); a rib condition determination step (Step 4) for determining rib conditions; a rib characteristic determination step (Step 5) for calculating a minimum value (Lrmin) for length of the ribs (12) in the direction of flow that satisfies the contact angle (θs) and strength requirements; a minimum value condition confirmation step (Step 6) for confirming whether or not a liquid film length (Lw(θs)) is greater than the minimum value (Lrmin); and a rib length determination step (Step 7) for determining the length of the ribs (12) in the direction of flow within a range of the liquid film length (Lw(θs)) from the minimum value (Lrmin).
