A dishwasher includes a case, injection arms, a sump including an injection flow path coupling portion, a washing pump for supplying washing water stored in the sump to the injection arms, and a switching valve including a flow path distributor for distributing washing water to injection arms. The flow path distributor defines distribution holes. When the flow path distributor is in a reference position, the distribution holes are positioned so that all of the injection arm supply holes are opened, and, when the flow path distributor is rotated by a first angle from a reference position, the distribution holes are positioned so that any one of the injection arm supply holes is opened. The injection flow path coupling portion includes a plurality of support ribs protruded toward the flow path distributor and including a support rib corresponding to at least one of the distribution holes.