Door/window comprising a frame intended to be embedded/anchored in a wall of a building and a mobile door/window assembly rotatably coupled to said frame provided with: - a panel provided with at least three glass sheets (5, 6, 7) rigidly fixed parallel to each other and comprising an external lateral sheet, an internal lateral sheet and a central sheet interposed between said lateral sheets (5, 6) and respectively separated therefrom by means of a first and a second channel (8, 9) adapted to define a corresponding first and second double glazing (10, 11); - a frame, formed by crosspieces and by uprights angularly joined together, perimetrically fixed to said panel and intended to support the panel with respect to said frame intended to be embedded/anchored in a wall of a building; said external lateral sheet, said internal lateral sheet and said central sheet of said panel being extended perimetrically beyond said double glazing (10, 11) for corresponding peripheral sections (5', 6', 7'), of which that relative to the central sheet is shorter than those relative to the lateral sheets (5', 6') and interposed therebetween; said frame comprising: - a central portion provided with a perimeter seat delimited by at least two parallel longitudinal walls and by a bottom placed to connect said longitudinal walls; - two lateral portions, of which one is internal and one is external, substantially interposed between the peripheral sections (5', 6') of said lateral sheets (5, 6), connected together by said central portion; characterized in that: said perimeter seat contains a structural sealing cord and being engaged by the peripheral section of said central sheet embedded in said structural sealing cord in order to support said panel; at least one of said lateral portions (19, 20) being susceptible to mechanically cooperate with connection means in order to angularly together join the uprights and the crosspieces of said frame. - a panel provided with at least three glass sheets (5, 6, 7) rigidly fixed parallel to each other and comprising an external lateral sheet, an internal lateral sheet and a central sheet interposed between said lateral sheets (5, 6) and respectively separated therefrom by means of a first and a second channel (8, 9) adapted to define a corresponding first and second double glazing (10, 11); - a frame, formed by crosspieces and by uprights angularly joined together, perimetrically fixed to said panel and intended to support the panel with respect to said frame intended to be embedded/anchored in a wall of a building; - a central portion provided with a perimeter seat delimited by at least two parallel longitudinal walls and by a bottom placed to connect said longitudinal walls; - two lateral portions, of which one is internal and one is external, substantially interposed between the peripheral sections (5', 6') of said lateral sheets (5, 6), connected together by said central portion; said perimeter seat contains a structural sealing cord and being engaged by the peripheral section of said central sheet embedded in said structural sealing cord in order to support said panel; at least one of said lateral portions (19, 20) being susceptible to mechanically cooperate with connection means in order to angularly together join the uprights and the crosspieces of said frame.