A connector that is difficult to be released from a state fitted to a mating connector when an unexpected external force acts on the connector, and is removed from the mating connector with a small operating force when intentionally releasing the fitted state. An unlocking member of the connector for releasing this connector from the fitted state includes a releasing portion for releasing an elastic locking portion of the mating connector from a state caught by a catching portion of a connector body fitted to the mating connector, and a sliding portion for sliding on the connector body. The connector body includes a supporting portion for slidably supporting the sliding portion. A guide surface is formed on the supporting portion for guiding the sliding portion such that the releasing portion is displaced toward the elastic locking portion, to thereby release the caught state.