A connector configured to be mated with and to be removed from a mating connector in an up-down direction, wherein: the mating connector comprises a plurality of camshafts; the connector comprises a housing, a lever, a slider, a press mechanism, and a retain mechanism; the housing is provided with a regulating portion; the lever is attached to the housing to be rotatable between an initial position and a mated position; the lever is provided with a regulated portion; the slider is attached to the housing to be movable between a front end position and a rear end position in a front-rear direction orthogonal to the up-down direction; the lever has a pinion portion having a plurality of teeth; the slider has a plurality of cam grooves and a rack portion having a plurality of teeth; the pinion portion and the rack portion translate turn of the lever into front-rear-direction movement of the slider by engaging with each other; according to the front-rear-direction movement of the slider, the cam grooves transmit up-down-direction force to the camshafts of the mating connector to move relatively the mating connector against the connector in the up-down direction; when the lever turns from the initial position to the mated position, the slider is moved from the rear end position to the front end position in the front-rear direction; when the slider is moved from the rear end position to the front end position, the connector comes into a mated state that the connector is mated with the mating connector; when the lever turns from the mated position to the initial position, the slider is moved from the front end position to the rear end position in the front-rear direction; when the slider is moved from the front end position to the rear end position, the connector comes into a removable state that the connector is removable from the mating connector; when the lever is in the mated position, the regulating portion regulates the regulated portion to limit movement of the lever toward the initial position; and when the lever is in the mated position, the retain mechanism retains the slider in the front end position, characterized in that when the lever is in the mated position, the press mechanism applies a force to the lever in a direction directed towards the initial position from the mated position to press the regulated portion against the regulating portion. the mating connector comprises a plurality of camshafts; the connector comprises a housing, a lever, a slider, a press mechanism, and a retain mechanism; the housing is provided with a regulating portion; the lever is attached to the housing to be rotatable between an initial position and a mated position; the lever is provided with a regulated portion; the slider is attached to the housing to be movable between a front end position and a rear end position in a front-rear direction orthogonal to the up-down direction; the lever has a pinion portion having a plurality of teeth; the slider has a plurality of cam grooves and a rack portion having a plurality of teeth; the pinion portion and the rack portion translate turn of the lever into front-rear-direction movement of the slider by engaging with each other; according to the front-rear-direction movement of the slider, the cam grooves transmit up-down-direction force to the camshafts of the mating connector to move relatively the mating connector against the connector in the up-down direction; when the lever turns from the initial position to the mated position, the slider is moved from the rear end position to the front end position in the front-rear direction; when the slider is moved from the rear end position to the front end position, the connector comes into a mated state that the connector is mated with the mating connector; when the lever turns from the mated position to the initial position, the slider is moved from the front end position to the rear end position in the front-rear direction; when the slider is moved from the front end position to the rear end position, the connector comes into a removable state that the connector is removable from the mating connector; when the lever is in the mated position, the regulating portion regulates the regulated portion to limit movement of the lever toward the initial position; and when the lever is in the mated position, the retain mechanism retains the slider in the front end position, characterized in that when the lever is in the mated position, the press mechanism applies a force to the lever in a direction directed towards the initial position from the mated position to press the regulated portion against the regulating portion.