A catalytic ink preparation method comprises mixing a first ion conducting body and a catalyst, preparing a first ink, and concentrating the first ink. The method is characterized by further comprising a step of adding a second ion conducting body to the concentrated first ink. With such a catalytic ink preparation method, the quantity of solvent in the first ion conducting body is reduced by concentration. In other words, the first ion conducting body adheres to the catalyst, and re-dissolution is not prone to occurring with the first ion conducting body when the second ion conducting body is added. Thus, it is possible to efficiently manufacture an electrode catalyst in which a significant part of the surface of the catalyst is covered with two ionomer layers, and there is almost no portion which is covered with only one ionomer layer.