A liquid ejection apparatus including an ejection head having a nozzle in which liquid is ejected through the nozzle, a plurality of cartridges that retain the liquid and supplies the liquid to the ejection head, and a switching mechanism that switches liquid to be supplied to the ejection head from a plurality of types of liquid supplied from the cartridges. The switching mechanism includes a body having a communication passage in communication with the ejection head, a first diaphragm chamber and a second diaphragm chamber that communicate with each other through the communication passage and located to facing each other, a first diaphragm and a second diaphragm arranged in the first diaphragm chamber and the second diaphragm chamber, respectively, and capable of opening and closing the communication passage, and an operation mechanism provided in the communication passage. The operation mechanism includes a first operation end and a second operation end that operate the first diaphragm and the second diaphragm, respectively, when the communication passage is opened to allow communication between at least one of the first and second diaphragm chambers and the ejection head, and an urging member that urges the first and second operation ends in a direction in which the communication passage is opened by the first and second diaphragms.