Fume extractor hood of the type that can be at least partially inserted into a seat formed in a ceiling, said ceiling having an outer surface and an inner surface at least partially defining said seat and opposite to the outer surface, said hood comprising: - a frame having at least one pair of opposite sides (3a, 3b), said frame being configured to be at least partially inserted into said seat; - at least one locking element arranged at one of said sides (3a, 3b) of said frame, said locking element comprising an extendable portion commutable between an extended configuration, in which it rests on said inner surface to retain said frame in said seat, and a retracted configuration, in which it is brought back inside a perimeter of said frame to allow the engagement and disengagement of said frame into/from said seat, said locking element comprising at least one elastic element associated with said extendable portion to push it from the retracted configuration to the extended configuration; said locking element comprises a gripping member connected to said extendable portion and being accessible when said frame is inserted into said seat, said gripping member being operable to bring back said extendable portion from the extended configuration to the retracted configuration; characterized in that said locking element comprises: - a rod having a first end connected to said extendable portion and a second end opposite to the first end, said gripping member being defined on said second end; - an arm, which is rotatably connected to said extendable portion to rotate with respect to said extendable portion, a guide formed on said arm, said first end of said rod being engaged in said guide for sliding along said guide; - a pin connecting said rod and said guide, said arm being rotatably connected to said rod through said pin. - a frame having at least one pair of opposite sides (3a, 3b), said frame being configured to be at least partially inserted into said seat; - at least one locking element arranged at one of said sides (3a, 3b) of said frame, said locking element comprising an extendable portion commutable between an extended configuration, in which it rests on said inner surface to retain said frame in said seat, and a retracted configuration, in which it is brought back inside a perimeter of said frame to allow the engagement and disengagement of said frame into/from said seat, said locking element comprising at least one elastic element associated with said extendable portion to push it from the retracted configuration to the extended configuration; said locking element comprises a gripping member connected to said extendable portion and being accessible when said frame is inserted into said seat, said gripping member being operable to bring back said extendable portion from the extended configuration to the retracted configuration; characterized in that said locking element comprises: - a rod having a first end connected to said extendable portion and a second end opposite to the first end, said gripping member being defined on said second end; - an arm, which is rotatably connected to said extendable portion to rotate with respect to said extendable portion, a guide formed on said arm, said first end of said rod being engaged in said guide for sliding along said guide; - a pin connecting said rod and said guide, said arm being rotatably connected to said rod through said pin. - a rod having a first end connected to said extendable portion and a second end opposite to the first end, said gripping member being defined on said second end; - an arm, which is rotatably connected to said extendable portion to rotate with respect to said extendable portion, a guide formed on said arm, said first end of said rod being engaged in said guide for sliding along said guide; - a pin connecting said rod and said guide, said arm being rotatably connected to said rod through said pin.