A connector (10, 10A) mateable with a mating connector (70, 70A) having a mating lock portion along a front-rear direction under a state where the mating connector is located forward of the connector in the front-rear direction, wherein: the connector comprises a contact (122, 124), a housing (20, 20A), a slider (50, 50A), a regulating portion (444, 444A) and an operation portion (442, 542A); the contact is held by the housing; the housing has a lock portion; the lock portion is supported to be movable between a lock position and a release position; under a mated state where the connector is mated with the mating connector, the lock portion is located at the lock position and locks the mating lock portion of the mating connector; the slider is attached to the housing to be movable in the front-rear direction; the slider has a release portion and a regulated portion (562, 544A); when the slider is moved in a release direction (negative X-direction) in parallel to the front-rear direction under the mated state, the release portion moves the lock portion from the lock position to the release position and releases the mating lock portion; under the mated state, the regulating portion faces the regulated portion in the release direction and regulates a movement of the slider along the release direction; and when the operation portion is operated to be pressed inward of the connector in an operation direction intersecting with the front-rear direction, at least one of the regulating portion and the regulated portion is moved, and the regulating portion does not regulate the movement of the slider, the operation portion is supported by an operation support portion (44, 54A) which extends along the front-rear direction and is resiliently deformable, characterized in that each of the regulating portion and the regulated portion is a vertical surface perpendicular to the front-rear direction when the operation portion is not resiliently deformed. the connector comprises a contact (122, 124), a housing (20, 20A), a slider (50, 50A), a regulating portion (444, 444A) and an operation portion (442, 542A); the contact is held by the housing; the housing has a lock portion; the lock portion is supported to be movable between a lock position and a release position; under a mated state where the connector is mated with the mating connector, the lock portion is located at the lock position and locks the mating lock portion of the mating connector; the slider is attached to the housing to be movable in the front-rear direction; the slider has a release portion and a regulated portion (562, 544A); when the slider is moved in a release direction (negative X-direction) in parallel to the front-rear direction under the mated state, the release portion moves the lock portion from the lock position to the release position and releases the mating lock portion; under the mated state, the regulating portion faces the regulated portion in the release direction and regulates a movement of the slider along the release direction; and when the operation portion is operated to be pressed inward of the connector in an operation direction intersecting with the front-rear direction, at least one of the regulating portion and the regulated portion is moved, and the regulating portion does not regulate the movement of the slider, the operation portion is supported by an operation support portion (44, 54A) which extends along the front-rear direction and is resiliently deformable, characterized in that each of the regulating portion and the regulated portion is a vertical surface perpendicular to the front-rear direction when the operation portion is not resiliently deformed.