Bistable electric valve, particularly for a system for recovery of petrol vapours in a motor-vehicle, comprising: a hollow housing in which there is defined a chamber having respective first and second openings (4a, 3a) between which a valve seat is defined; an obturator movable inside said chamber and adapted to cooperate with said valve seat for controlling a flow of fluid between said openings (4a, 3a); a ferromagnetic core mounted movably inside the housing and connected to the obturator; first and second permanent magnets (11, 12) mounted in the housing and adapted to keep the ferromagnetic core in first and second working positions, respectively, in which the associated obturator closes and opens the valve seat, respectively; and a control solenoid arranged around the displacement path of the ferromagnetic core and adapted to generate a magnetic flux capable of causing the attraction of said core towards either one of said first and second working positions; the electric valve being characterized in that the obturator is displaceable with respect to the ferromagnetic core from and towards the valve seat, and the obturator has associated resilient means tending to urge it towards said seat; the arrangement being such that when the ferromagnetic core is in said first position, said resilient means keep the obturator against the valve seat, allowing the obturator to move away from said seat when the fluid pressure upstream of said seat exceeds a predetermined value; and when the control solenoid is energized while the ferromagnetic core is in the first working position and the obturator closes the valve seat, said resilient means cause the application onto said core of a force tending to displace it towards the second working position, cooperating with the control solenoid so as to determine opening of the electric valve. a hollow housing in which there is defined a chamber having respective first and second openings (4a, 3a) between which a valve seat is defined; an obturator movable inside said chamber and adapted to cooperate with said valve seat for controlling a flow of fluid between said openings (4a, 3a); a ferromagnetic core mounted movably inside the housing and connected to the obturator; first and second permanent magnets (11, 12) mounted in the housing and adapted to keep the ferromagnetic core in first and second working positions, respectively, in which the associated obturator closes and opens the valve seat, respectively; and a control solenoid arranged around the displacement path of the ferromagnetic core and adapted to generate a magnetic flux capable of causing the attraction of said core towards either one of said first and second working positions; the electric valve being characterized in that the obturator is displaceable with respect to the ferromagnetic core from and towards the valve seat, and the obturator has associated resilient means tending to urge it towards said seat; the arrangement being such that when the ferromagnetic core is in said first position, said resilient means keep the obturator against the valve seat, allowing the obturator to move away from said seat when the fluid pressure upstream of said seat exceeds a predetermined value; and when the control solenoid is energized while the ferromagnetic core is in the first working position and the obturator closes the valve seat, said resilient means cause the application onto said core of a force tending to displace it towards the second working position, cooperating with the control solenoid so as to determine opening of the electric valve.