A monolith-type reactor includes a separation membrane, a first flow path, a second flow path, and a catalyst. The separation membrane is permeable to a product of conversion reaction of a raw material gas containing at least hydrogen and carbon dioxide to a liquid fuel. The raw material gas flows through the first flow path. A sweep gas for sweeping the product that has permeated through the separation membrane flows through the second flow path. The catalyst is disposed in the first flow path and configured to promote the conversion reaction of the raw material gas to the liquid fuel. In a side view of the separation membrane, a direction in which the sweep gas flows through the second flow path is opposite to the direction in which the raw material gas flows through the first flow path.