A fluid flow channel device comprising: a ceramic main body including a plurality of internal flow channels having an inlet (10S1) and an outlet (10S2) that are independent of each other and allowing fluid to flow along at least one flow channel surface, and at least one outer surface; and a non-ceramic sub-body including at least one inner surface and at least one fluid supply path allowing fluid to flow therethrough and having a supply port exposed to the at least one inner surface and supplying fluid to the plurality of internal flow channels collectively, and at least one fluid recovery path allowing fluid to flow therethrough and including a recovery port exposed to the at least one inner surface and receiving fluid from the plurality of internal flow channels collectively, the at least one inner surface being disposed in close contact with the at least one outer surface of the main body, characterized in that the at least one outer surface of the main body is orthogonal to the at least one flow channel surface, the inlets of the plurality of internal flow channels are disposed so as to be adjacent to each other and exposed to the at least one outer surface, the outlets (10S2) of the plurality of internal flow channels are disposed so as to be adjacent to each other and exposed to the at least one outer surface, the supply port of the sub-body is disposed opposite to the plurality of inlets (10S1) of the plurality of internal flow channels so as to cover the inlets (10S1), and the recovery port of the sub-body is disposed opposite to the plurality of outlets (10S2) of the plurality of internal flow channels so as to cover the outlets (10S2). a ceramic main body including a plurality of internal flow channels having an inlet (10S1) and an outlet (10S2) that are independent of each other and allowing fluid to flow along at least one flow channel surface, and at least one outer surface; and a non-ceramic sub-body including at least one inner surface and at least one fluid supply path allowing fluid to flow therethrough and having a supply port exposed to the at least one inner surface and supplying fluid to the plurality of internal flow channels collectively, and at least one fluid recovery path allowing fluid to flow therethrough and including a recovery port exposed to the at least one inner surface and receiving fluid from the plurality of internal flow channels collectively, the at least one inner surface being disposed in close contact with the at least one outer surface of the main body, characterized in that the at least one outer surface of the main body is orthogonal to the at least one flow channel surface, the inlets of the plurality of internal flow channels are disposed so as to be adjacent to each other and exposed to the at least one outer surface, the outlets (10S2) of the plurality of internal flow channels are disposed so as to be adjacent to each other and exposed to the at least one outer surface, the supply port of the sub-body is disposed opposite to the plurality of inlets (10S1) of the plurality of internal flow channels so as to cover the inlets (10S1), and the recovery port of the sub-body is disposed opposite to the plurality of outlets (10S2) of the plurality of internal flow channels so as to cover the outlets (10S2).