Disclosed is a method for producing a catalyst, wherein the method comprises: a supplying step of supplying a dispersion containing a palladium-containing fine particle from a supplying part into a reaction container; a preparing step of preparing a copper-palladium-containing complex in which at least part of a surface of the palladium-containing fine particle is covered with copper, by passing the dispersion through a reacting part and bringing the palladium-containing fine particle in the dispersion into contact with a copper-containing member in the reacting part; and a substituting step of substituting the copper in the copper-palladium-containing complex emitted from an emitting part with platinum by bringing the complex into contact with a platinum-containing solution.