The invention provides a connector that facilitates the attaching and detaching work and is to be attached in a narrow space, as well as a wire harness using the connector. Two terminal housings (5, 7) are fitted in a direction intersecting with an extending direction of a cable (61a-61c). The connector comprises a first fitting portion (31) arranged in the first terminal housing (5); a second fitting portion (41) arranged in the second termian housing (7); and a fitted-state maintaining member (70) that is configured so as to be fitted to both the first and second fitting portions by being slid along a direction perpendicular to the fitting direction of the two terminal housings after the two terminal housings are fitted to each other.