A motor-driven sliding door or window comprising: - a fixed frame ; - a sash which slides horizontally relative to the frame , between an open position and a closed position; - at least one carriage , associated, in use, on a lower crosspiece of the sash and resting on a horizontal base track to allow the sliding of the sash in both the opening and closing directions; - locking / unlocking elements , located on operating rods which slide along at least one vertical upright of the sash ; the locking / unlocking elements interacting with corresponding striker elements positioned on the frame fixed at least in order to lock/unlock the sash between the closed position and the open position and vice versa; - a control unit composed of a kinematic unit connected, on one side, to the operating rods and, on the other side, to an activating element for controlling the sliding movement of the rods , in both directions, and allow the configurations for opening and closing the sash ; the control unit comprising a box-shaped body positioned inside the vertical upright of the sash ; the box-shaped body housing the kinematic unit connected, using a drive element , to the operating rods and an element motor-driven by a source of outside energy, defining the activation unit, connected to the kinematic unit for activating the operating rods by external control; characterised in that the kinematic unit has elements for connection / separation between the drive element and the motor-driven element to allow, when required, an emergency manual movement of the rods using a shaft of a handle connectable, from the outside, to the drive unit through a cavity made on the vertical upright of the sash ; the connecting / separating elements being movable between a connected position between the drive unit and the motor-driven element , and a separated position between the drive element and the motor-driven element which can be activated, in use, at the inlet of the shaft of the handle . - a fixed frame ; - a sash which slides horizontally relative to the frame , between an open position and a closed position; - at least one carriage , associated, in use, on a lower crosspiece of the sash and resting on a horizontal base track to allow the sliding of the sash in both the opening and closing directions; - locking / unlocking elements , located on operating rods which slide along at least one vertical upright of the sash ; the locking / unlocking elements interacting with corresponding striker elements positioned on the frame fixed at least in order to lock/unlock the sash between the closed position and the open position and vice versa; - a control unit composed of a kinematic unit connected, on one side, to the operating rods and, on the other side, to an activating element for controlling the sliding movement of the rods , in both directions, and allow the configurations for opening and closing the sash ; the control unit comprising a box-shaped body positioned inside the vertical upright of the sash ; the box-shaped body housing the kinematic unit connected, using a drive element , to the operating rods and an element motor-driven by a source of outside energy, defining the activation unit, connected to the kinematic unit for activating the operating rods by external control; characterised in that the kinematic unit has elements for connection / separation between the drive element and the motor-driven element to allow, when required, an emergency manual movement of the rods using a shaft of a handle connectable, from the outside, to the drive unit through a cavity made on the vertical upright of the sash ; the connecting / separating elements being movable between a connected position between the drive unit and the motor-driven element , and a separated position between the drive element and the motor-driven element which can be activated, in use, at the inlet of the shaft of the handle . <EOS>