Automatic maintenance system of a tennis court (2, 2a, 2b, 2c) comprising: (a) at least one robot (2, 2a, 2b, 2c) comprising a housing (58, 60a, 60b, 60c) containing one or more tennis court maintenance elements (34, 46; 36, 38; 40, 42; 62; 64, 68; 70, 72) which has a width corresponding at least to the extension of the end line, preferably to the distance of the double posts supporting the court net and which is equipped with motion means (4, 6, 8, 10) for moving said robot (2, 2a, 2b, 2c); a control unit for controlling said tennis court maintenance elements and said motion means (4, 6, 8, 10), wherein said tennis court maintenance element(s) is/are selected between a court covering unit containing a rolled up tarpaulin on a relative axis which can be actuated with a rotation movement, a grass cutting unit, a line tracing unit (40, 42), a smoothing unit, a wetting unit (68, 64), a cleaning unit (70, 72) and combinations thereof; and (b) a communication device for communication with said control unit to allow remote management of said court maintenance elements (36, 38; 40, 42; 62; 64, 68; 70, 72) and of the motion means (4, 6, 8, 10), characterized in that said automatic maintenance system further comprises (c) a supplying station for each robot locatable/located behind the end line of the tennis court; wherein said supplying station comprises: (α) fixing means, preferably magnetic hooks, to be able to reversibly attach said tarpaulin which in this regard is equipped with respective second fixing means which can be coupled to said first fixing means; and/or (β) in the presence of a wetting unit (64, 68), a hydraulic attachment for filling the water tank; and/or (γ) devices for charging the battery(s) inside the robot. (a) at least one robot (2, 2a, 2b, 2c) comprising a housing (58, 60a, 60b, 60c) containing one or more tennis court maintenance elements (34, 46; 36, 38; 40, 42; 62; 64, 68; 70, 72) which has a width corresponding at least to the extension of the end line, preferably to the distance of the double posts supporting the court net and which is equipped with motion means (4, 6, 8, 10) for moving said robot (2, 2a, 2b, 2c); a control unit for controlling said tennis court maintenance elements and said motion means (4, 6, 8, 10), wherein said tennis court maintenance element(s) is/are selected between a court covering unit containing a rolled up tarpaulin on a relative axis which can be actuated with a rotation movement, a grass cutting unit, a line tracing unit (40, 42), a smoothing unit, a wetting unit (68, 64), a cleaning unit (70, 72) and combinations thereof; and motion means (4, 6, 8, 10) for moving said robot (2, 2a, 2b, 2c); a control unit for controlling said tennis court maintenance elements and said motion means (4, 6, 8, 10), (b) a communication device for communication with said control unit to allow remote management of said court maintenance elements (36, 38; 40, 42; 62; 64, 68; 70, 72) and of the motion means (4, 6, 8, 10), characterized in that said automatic maintenance system further comprises (c) a supplying station for each robot locatable/located behind the end line of the tennis court; wherein said supplying station comprises: (α) fixing means, preferably magnetic hooks, to be able to reversibly attach said tarpaulin which in this regard is equipped with respective second fixing means which can be coupled to said first fixing means; and/or (β) in the presence of a wetting unit (64, 68), a hydraulic attachment for filling the water tank; and/or (γ) devices for charging the battery(s) inside the robot. (α) fixing means, preferably magnetic hooks, to be able to reversibly attach said tarpaulin which in this regard is equipped with respective second fixing means which can be coupled to said first fixing means; and/or (β) in the presence of a wetting unit (64, 68), a hydraulic attachment for filling the water tank; and/or (γ) devices for charging the battery(s) inside the robot.