The invention relates to an apparatus (1) for electrostatically spraying a coating product, said apparatus including an sprayer (1) provided with a first pipe (4) and with a second pipe (5), in which pipes the flow of coating product and air is controlled by at least one valve (6, 7). Said sprayer (1) includes means (15) for controlling the opening/closing of the valve, a high voltage unit (10), as well as a generator (8) for supplying power to the high voltage unit (10). In addition, a module (12) for controlling the power supplied to the high tension unit is included in the generator (8). The sprayer (1) also includes at least one first sensor (17) suitable for detecting the position of a shutter (62, 72) of the valve (6, 7) relative to a seat (64, 74) and for outputting a signal (S1) that can be used by the control module (12) in order to control the power supplied to the high voltage unit (10), as well as a second sensor (18) suitable for detecting the position of a switch (19) positioned on the spray gun (1) and for outputting a signal (S1) that can be used by the control module (12) in order to control the power supply (8) of the high tension unit(10).