A reactor for carrying out a chemical process, comprising a plurality of simple plates stacked together in layers, said reactor including at least two chemical reactant inlet ports and at least one product outlet port for the receipt and discharge of a chemical product, at least two inlet pathways for accommodating the chemical reactants, wherein each inlet pathway is connected in fluid communication with a different one of said chemical reactant inlet ports, said at least two inlet pathways merging within the reactor to form at least one reaction chamber in which at least two chemical reactants can react to generate a chemical product, at least one outlet pathway coupling said at least one reaction chamber in fluid communication with said at least one product outlet port, and wherein each chemical reactant inlet port, inlet pathway, reaction chamber and product outlet port comprises an opening through at least one simple plate aligned with at least a portion of an opening through an adjacent simple plate.