A window or a door has a fixed frame and a sash movable relative to the fixed frame. The sash is supported on a running rail of the fixed frame via at least one carriage with at least one roller. The sash can be moved transversely/perpendicularly to the main plane of the fixed frame by a control arm, wherein a roller part of the carriage moves in a straight line with respect to a sash part of the carriage. The control arm is supported on the fixed frame via the roller of the roller part and/or via a support part. The control arm is actuated by the longitudinal movement of a drive rod, the movement imparted via a pin, which is guided in a slot. The slot guides the pin on both sides with both control flanks, except for the play necessary to move the pin in the slot.