Thermostatic valve for controlling a gas stove, comprising - a valve body in which at least one gas inlet duct is made which can be connected to an inlet pipe from a tank, at least a first gas outlet duct which can be connected to an exit pipe leading to a main burner of the stove, and a second gas outlet duct which can be connected to a pilot burner, wherein the valve body houses at least a first interception element suitable to regulate the passage of gas from the inlet duct to the first outlet duct and a second interception element suitable to regulate the passage of gas from the inlet duct to the second outlet duct, said interception elements comprising respective first and second actuator stems (18', 20') protruding from the valve body; - an adjustment knob which engages said actuator stems and which is rotatable between an off position, wherein both the first interception element and the second interception element prevent the passage of gas towards the respective outlet ducts, a stand-by position, in which the first interception element is controlled by the adjustment knob to prevent the passage of gas from the inlet duct to the first outlet duct and wherein the second interception element allows the passage of the gas from the inlet duct to the second outlet duct, and an adjustment position, wherein both the first interception element and the second interception element allow the passage of gas towards the respective outlet ducts, wherein the adjustment knob has a lower pilot burner control appendage which, once the second interception element has been pushed into the open position, keeps such interception element in the open position when the knob is rotated in a temperature increase direction which allows the rotation of the first actuator stem in a direction of progressive opening of the first interception element, wherein the adjustment knob is fitted with a lower limit switch appendage which defines, with the lower pilot burner control appendage, a shutdown window which allows the second actuator stem to rise up into the closed position, said lower limit switch appendage being suitable to abut against an end portion of the second actuator stem, characterized in that said thermostatic valve comprises a stop member suitable to prevent a rotation of the adjustment knob from the stand-by position to the complete off position, wherein the stop member is made in a retention bracket secured to the valve body and extending around the adjustment knob, wherein a bracket opening is made in the retention bracket, for example of a substantially circular shape, through which the adjustment knob extends, the stop member consisting of a radial retention tooth which extends into the bracket opening in order to engage the lower limit switch appendage and so as to allow the lower pilot burner control appendage to rotate above it. - a valve body in which at least one gas inlet duct is made which can be connected to an inlet pipe from a tank, at least a first gas outlet duct which can be connected to an exit pipe leading to a main burner of the stove, and a second gas outlet duct which can be connected to a pilot burner, wherein the valve body houses at least a first interception element suitable to regulate the passage of gas from the inlet duct to the first outlet duct and a second interception element suitable to regulate the passage of gas from the inlet duct to the second outlet duct, said interception elements comprising respective first and second actuator stems (18', 20') protruding from the valve body; - an adjustment knob which engages said actuator stems and which is rotatable between an off position, wherein both the first interception element and the second interception element prevent the passage of gas towards the respective outlet ducts, a stand-by position, in which the first interception element is controlled by the adjustment knob to prevent the passage of gas from the inlet duct to the first outlet duct and wherein the second interception element allows the passage of the gas from the inlet duct to the second outlet duct, and an adjustment position, wherein both the first interception element and the second interception element allow the passage of gas towards the respective outlet ducts, wherein the adjustment knob has a lower pilot burner control appendage which, once the second interception element has been pushed into the open position, keeps such interception element in the open position when the knob is rotated in a temperature increase direction which allows the rotation of the first actuator stem in a direction of progressive opening of the first interception element, wherein the adjustment knob is fitted with a lower limit switch appendage which defines, with the lower pilot burner control appendage, a shutdown window which allows the second actuator stem to rise up into the closed position, said lower limit switch appendage being suitable to abut against an end portion of the second actuator stem, characterized in that said thermostatic valve comprises a stop member suitable to prevent a rotation of the adjustment knob from the stand-by position to the complete off position, wherein the stop member is made in a retention bracket secured to the valve body and extending around the adjustment knob, wherein a bracket opening is made in the retention bracket, for example of a substantially circular shape, through which the adjustment knob extends, the stop member consisting of a radial retention tooth which extends into the bracket opening in order to engage the lower limit switch appendage and so as to allow the lower pilot burner control appendage to rotate above it.