Disclosed is a micro-macro channel reactor comprising: a top end plate and a bottom end plate assembled on the outskirts of the micro-macro channel reactor; a heat exchanging plate by which a heat exchanging material passes through passages thereof so that heat is transferred between the heat exchanging material and such a fluid as a reactant, a product, or a mixture thereof that passes through a catalyst plate; a catalyst plate stacked and assembled together with the heat exchanging plate and including a catalyst section containing a reaction catalyst necessary to perform a catalytic reaction of the reactant while the reactant is passing through the catalyst section; and a support plate stacked and assembled together with the catalyst plate and configured to provide passages that allows the reactant to pass through the catalyst section of the catalyst plate.