A flow channel switching valve comprising: a valve body in which a valve chamber is formed in its inner portion and which has a cylindrical barrel portion provided with a plurality of outflow ports (11a, 11b) in its outer peripheral portion; a valve element in which a plurality of communication ports (22a, 22b) are formed in a peripheral direction and which has a cylindrical valve element portion with an upper opening that is occluded and rotatably arranged within said valve chamber, a rotation drive unit for rotating said valve element; a seal member which is interposed between the cylindrical barrel portion of said valve body and the cylindrical valve element portion of said valve element so as to suppress leakage of a fluid between said valve chamber and each of the outflow ports (11a, 11b); and the flow channel switching valve being structured such that said cylindrical valve element portion rotationally slides around an inner peripheral side of said seal member so as to open and close or switch said outflow port (11a, 11b) of said valve body, by rotating said cylindrical valve element portion of said valve element within said valve chamber by said rotation drive unit, wherein a bridging portion (19a, 19b) connecting two end portions in the peripheral direction of said communication port (22a, 22b) is provided in each of the communication ports (22a, 22b) in said cylindrical valve element portion of said valve element, said bridging portion (19a, 19b) having a thickness that is the same as a thickness of the cylindrical valve element portion the seal member comprises a plurality of openings (31a, 31b, 31c, 31d) for communicating with the communication ports (22a, 22b) and the seal member surrounds the cylindrical valve element portion. a valve body in which a valve chamber is formed in its inner portion and which has a cylindrical barrel portion provided with a plurality of outflow ports (11a, 11b) in its outer peripheral portion; a valve element in which a plurality of communication ports (22a, 22b) are formed in a peripheral direction and which has a cylindrical valve element portion with an upper opening that is occluded and rotatably arranged within said valve chamber, a rotation drive unit for rotating said valve element; a seal member which is interposed between the cylindrical barrel portion of said valve body and the cylindrical valve element portion of said valve element so as to suppress leakage of a fluid between said valve chamber and each of the outflow ports (11a, 11b); and the flow channel switching valve being structured such that said cylindrical valve element portion rotationally slides around an inner peripheral side of said seal member so as to open and close or switch said outflow port (11a, 11b) of said valve body, by rotating said cylindrical valve element portion of said valve element within said valve chamber by said rotation drive unit, wherein a bridging portion (19a, 19b) connecting two end portions in the peripheral direction of said communication port (22a, 22b) is provided in each of the communication ports (22a, 22b) in said cylindrical valve element portion of said valve element, said bridging portion (19a, 19b) having a thickness that is the same as a thickness of the cylindrical valve element portion the seal member comprises a plurality of openings (31a, 31b, 31c, 31d) for communicating with the communication ports (22a, 22b) and the seal member surrounds the cylindrical valve element portion.