A device for generating an electromagnetic field alternating radio frequency in an area (3) working, comprising: - an applicator (2) to emit the electromagnetic field in the area (3) work - an oscillator (4) to provide a voltage (VRF) alternating and direct current (IRF) alternating with a predetermined value and a predetermined frequency - means (5) for power supply supplying a voltage (VCC) to said oscillator substantially CD and - means (6) associated control to said means (5) for power supply to control the electrical parameters of said AC voltage AC (VRF), CA (IRF) current and / or frequency supplied to said applicator (2) said oscillator (4) wherein said means (6) control comprises a port (7) input connected to the network (N) of electrical power, a first circuit (8) electronic control is connected to said port (7) input to vary substantially instantaneously said electrical parameters and instantaneously control the power field emission, and a second circuit (10) electronic control for regulating the operation of said oscillator (4), wherein said first circuit (8) e has a port (9 ) output connected to said means (5) power supply, and wherein said oscillator (4) comprises a triode (19) having a terminal (G) grid, wherein the device is characterized in that said first circuit (8 ) electronic control is an inverter (11) adapted to convert the voltage (N) network having a constant frequency and a constant RMS value in a CA (VINV) voltage having a MS value controlled and / or contro frequency lada being connected said second circuit (10) electronic control terminal (G) grid of said triode (19) to control the voltage (VG) of grid according to the instantaneous value of said AC voltage (VINV) in output (14) of said inverter (11).Un dispositivo para generar un campo electromagnético de radiofrecuencia alterno en un área (3) de trabajo, que comprende: - un aplicador (2) para emitir el campo electromagnético en el área (3) de trabajo - un oscilador (4) para proporcionar
