A plug connector, in particular a circuit board plug connector, having a) a first plug connector part and a second plug connector part, wherein one of the plug connector parts is preferably a socket part and the other of the plug connector parts is preferably a pin part, b) and having at least one locking device, which secures the two plug connector parts (2, 3), which are coupled to one another, against unintentional disengagement in a locking position and which is movable, in particular displaceable and/or pivotable, in a holding device of the second plug connector part, c) wherein the plug connector parts (2, 3) each have multiple contacts, which are preferably arranged in at least one row and are to be connected to one another, in the region of their plug faces, d) the locking device and the holding device are each arranged between two of the contacts in the at least one row of the contacts to be connected to one another, characterized in that e) the locking device is arranged so it is pivotable on the first plug connector part, f) the locking device has a catch cam, which is pivotable relative to the first plug connector part, and which is locked in a latching manner on the second plug connector part when the two plug connector parts are pushed together, and g) the locking device has a tongue, on the free end of which the catch hook or catch cam is formed, which has an intake bevel, wherein the tongue is connected, in a region located remotely from the catch hook, via a web to the second plug connector part, and h) wherein an actuating bow is formed on the tongue, which is designed and arranged such that, by pressing on the actuating bow perpendicularly to the plugging direction, the tongue having the catch cam is pivotable substantially perpendicularly to the plugging direction. a) a first plug connector part and a second plug connector part, wherein one of the plug connector parts is preferably a socket part and the other of the plug connector parts is preferably a pin part, b) and having at least one locking device, which secures the two plug connector parts (2, 3), which are coupled to one another, against unintentional disengagement in a locking position and which is movable, in particular displaceable and/or pivotable, in a holding device of the second plug connector part, c) wherein the plug connector parts (2, 3) each have multiple contacts, which are preferably arranged in at least one row and are to be connected to one another, in the region of their plug faces, d) the locking device and the holding device are each arranged between two of the contacts in the at least one row of the contacts to be connected to one another, characterized in that e) the locking device is arranged so it is pivotable on the first plug connector part, f) the locking device has a catch cam, which is pivotable relative to the first plug connector part, and which is locked in a latching manner on the second plug connector part when the two plug connector parts are pushed together, and g) the locking device has a tongue, on the free end of which the catch hook or catch cam is formed, which has an intake bevel, wherein the tongue is connected, in a region located remotely from the catch hook, via a web to the second plug connector part, and h) wherein an actuating bow is formed on the tongue, which is designed and arranged such that, by pressing on the actuating bow perpendicularly to the plugging direction, the tongue having the catch cam is pivotable substantially perpendicularly to the plugging direction.