A mower adapted to be moved along a field with plants to be cut, the mower comprising: - at least one cutter mounted on the mower via a carrier and adapted to cut the plants, and - a safety system comprising: ∘ a control unit, ∘ at least one detector adapted to: • detect a presence of an obstacle in front of the at least one cutter and within a predefined distance from the at least one cutter, and ▪ provide a warning signal to the control unit when the presence of the obstacle is detected, and ∘ at least one safety device adapted to cause a separation between the obstacle and the at least one cutter while the mower is moved forwards, - wherein the control unit provides a separation signal to the at least one safety device in response to receiving the warning signal, - wherein the at least one safety device causes the separation in response to receiving the separation signal, and - wherein the safety system is configured so that the separation is caused fast enough to ensure that the obstacle is not hit by the at least one cutter while the mower is moved forwards at working speed; characterized in that said at least one safety device comprises at least one shield which is movable between a retracted position in which it does not cover the at least one cutter and a protecting position in which it extends in front of the at least one cutter to prevent contact between the at least one cutter and the obstacle. - at least one cutter mounted on the mower via a carrier and adapted to cut the plants, and - a safety system comprising: ∘ a control unit, ∘ at least one detector adapted to: • detect a presence of an obstacle in front of the at least one cutter and within a predefined distance from the at least one cutter, and ▪ provide a warning signal to the control unit when the presence of the obstacle is detected, and ∘ at least one safety device adapted to cause a separation between the obstacle and the at least one cutter while the mower is moved forwards, - wherein the control unit provides a separation signal to the at least one safety device in response to receiving the warning signal, - wherein the at least one safety device causes the separation in response to receiving the separation signal, and - wherein the safety system is configured so that the separation is caused fast enough to ensure that the obstacle is not hit by the at least one cutter while the mower is moved forwards at working speed; ∘ a control unit, ∘ at least one detector adapted to: • detect a presence of an obstacle in front of the at least one cutter and within a predefined distance from the at least one cutter, and ▪ provide a warning signal to the control unit when the presence of the obstacle is detected, and • detect a presence of an obstacle in front of the at least one cutter and within a predefined distance from the at least one cutter, and ▪ provide a warning signal to the control unit when the presence of the obstacle is detected, and ∘ at least one safety device adapted to cause a separation between the obstacle and the at least one cutter while the mower is moved forwards, - wherein the control unit provides a separation signal to the at least one safety device in response to receiving the warning signal, - wherein the at least one safety device causes the separation in response to receiving the separation signal, and - wherein the safety system is configured so that the separation is caused fast enough to ensure that the obstacle is not hit by the at least one cutter while the mower is moved forwards at working speed; - wherein the control unit provides a separation signal to the at least one safety device in response to receiving the warning signal, - wherein the at least one safety device causes the separation in response to receiving the separation signal, and - wherein the safety system is configured so that the separation is caused fast enough to ensure that the obstacle is not hit by the at least one cutter while the mower is moved forwards at working speed;