A dishwasher, comprising: a case for receiving a washing object; a plurality of injection arms (13, 14, 15) for injecting washing water into the case; a sump disposed at a lower side of the case to store the washing water and comprising an injection flow path coupling portion in which a plurality of injection arm supply holes (1071a, 1071b, 1071c) communicating with the plurality of injection arms (13, 14, 15) are respectively formed; a washing pump for supplying the washing water stored in the sump to the plurality of injection arms (13, 14, 15) through the injection flow path coupling portion; and a switching valve disposed in the injection flow path coupling portion and comprising a flow path distributor for distributing washing water to at least one of the plurality of injection arms (13, 14, 15), wherein the flow path distributor has a plurality of distribution holes (1311, 1312) and is rotatably disposed in the injection flow path coupling portion, (i) when the flow path distributor is in a reference position, the plurality of distribution holes (1311, 1312) are positioned so that all of the plurality of injection arm supply holes (1071a, 1071b, 1071c) are opened, and (ii) when the flow path distributor is rotated by a first angle (θ1) from a reference position, the plurality of distribution holes (1311, 1312) are positioned so that any one of the plurality of injection arm supply holes (1071a, 1071b, 1071c) is opened, characterized in that: the injection flow path coupling portion comprises a plurality of support ribs (1075a, 1075b, 1076a, 1076b, 1076c), protruded toward the flow path distributor, including: corresponding ribs (1076a, 1076b, 1076c) formed in a shape corresponding to at least one of the plurality of distribution holes (1311, 1312) of the flow path distributor in a state rotated by a first angle (θ1) from the reference position, and a plurality of concentric circle ribs (1075a, 1075b) disposed on a concentric circle from a center of rotation of the flow path distributor. a case for receiving a washing object; a plurality of injection arms (13, 14, 15) for injecting washing water into the case; a sump disposed at a lower side of the case to store the washing water and comprising an injection flow path coupling portion in which a plurality of injection arm supply holes (1071a, 1071b, 1071c) communicating with the plurality of injection arms (13, 14, 15) are respectively formed; a washing pump for supplying the washing water stored in the sump to the plurality of injection arms (13, 14, 15) through the injection flow path coupling portion; and a switching valve disposed in the injection flow path coupling portion and comprising a flow path distributor for distributing washing water to at least one of the plurality of injection arms (13, 14, 15), wherein the flow path distributor has a plurality of distribution holes (1311, 1312) and is rotatably disposed in the injection flow path coupling portion, (i) when the flow path distributor is in a reference position, the plurality of distribution holes (1311, 1312) are positioned so that all of the plurality of injection arm supply holes (1071a, 1071b, 1071c) are opened, and (ii) when the flow path distributor is rotated by a first angle (θ1) from a reference position, the plurality of distribution holes (1311, 1312) are positioned so that any one of the plurality of injection arm supply holes (1071a, 1071b, 1071c) is opened, (i) when the flow path distributor is in a reference position, the plurality of distribution holes (1311, 1312) are positioned so that all of the plurality of injection arm supply holes (1071a, 1071b, 1071c) are opened, and (ii) when the flow path distributor is rotated by a first angle (θ1) from a reference position, the plurality of distribution holes (1311, 1312) are positioned so that any one of the plurality of injection arm supply holes (1071a, 1071b, 1071c) is opened, characterized in that: the injection flow path coupling portion comprises a plurality of support ribs (1075a, 1075b, 1076a, 1076b, 1076c), protruded toward the flow path distributor, including: corresponding ribs (1076a, 1076b, 1076c) formed in a shape corresponding to at least one of the plurality of distribution holes (1311, 1312) of the flow path distributor in a state rotated by a first angle (θ1) from the reference position, and a plurality of concentric circle ribs (1075a, 1075b) disposed on a concentric circle from a center of rotation of the flow path distributor. corresponding ribs (1076a, 1076b, 1076c) formed in a shape corresponding to at least one of the plurality of distribution holes (1311, 1312) of the flow path distributor in a state rotated by a first angle (θ1) from the reference position, and a plurality of concentric circle ribs (1075a, 1075b) disposed on a concentric circle from a center of rotation of the flow path distributor.