A safety belt, in particular for an aircraft seat, comprising: - a closing buckle comprising a male element and a female element, - a first strap connected to the male element and a second strap connected to the female element, - the first strap and the second strap being able to be attached together by means of the closing buckle which can pass from an open state to a closed state by bringing the male element and the female element into cooperation with one another, wherein said safety belt further comprises: - a system for detecting the closing state of the seat belt and for generating information relating to a closing state of the seat belt, and - a system for detecting the state of mechanical tension of the seat belt and for generating information relating to a state of mechanical tension of at least one strap of the seat belt, - the system for detecting the closing state comprising: - a magnetic element arranged on one of the female element and the male element of the closing buckle, and - a magnetic field sensor arranged on the other of the female element and the male element of the closing buckle, - the magnetic sensor of the system for detecting the closing state of the seat belt, and the system for detecting the state of mechanical tension of the seat belt being arranged on the same male or female element of the seat belt, - the system for detecting the mechanical tension state comprising an elastic member and a switch arranged between a portion of a strap buckle and a portion of a male element or female element, such that when a mechanical tension applied to a strap (15, 16) exceeds a threshold the strap deforms the elastic member and triggers the switch to indicate that the seat belt is sufficiently tight around a portion of a passenger's body. - a closing buckle comprising a male element and a female element, - a first strap connected to the male element and a second strap connected to the female element, - the first strap and the second strap being able to be attached together by means of the closing buckle which can pass from an open state to a closed state by bringing the male element and the female element into cooperation with one another, - a system for detecting the closing state of the seat belt and for generating information relating to a closing state of the seat belt, and - a system for detecting the state of mechanical tension of the seat belt and for generating information relating to a state of mechanical tension of at least one strap of the seat belt, - the system for detecting the closing state comprising: - a magnetic element arranged on one of the female element and the male element of the closing buckle, and - a magnetic field sensor arranged on the other of the female element and the male element of the closing buckle, - the magnetic sensor of the system for detecting the closing state of the seat belt, and the system for detecting the state of mechanical tension of the seat belt being arranged on the same male or female element of the seat belt, - the system for detecting the mechanical tension state comprising an elastic member and a switch arranged between a portion of a strap buckle and a portion of a male element or female element, such that when a mechanical tension applied to a strap (15, 16) exceeds a threshold the strap deforms the elastic member and triggers the switch to indicate that the seat belt is sufficiently tight around a portion of a passenger's body. - a magnetic element arranged on one of the female element and the male element of the closing buckle, and - a magnetic field sensor arranged on the other of the female element and the male element of the closing buckle, - the magnetic sensor of the system for detecting the closing state of the seat belt, and the system for detecting the state of mechanical tension of the seat belt being arranged on the same male or female element of the seat belt, - the system for detecting the mechanical tension state comprising an elastic member and a switch arranged between a portion of a strap buckle and a portion of a male element or female element, such that when a mechanical tension applied to a strap (15, 16) exceeds a threshold the strap deforms the elastic member and triggers the switch to indicate that the seat belt is sufficiently tight around a portion of a passenger's body.