Door/window comprising a frame (3) and a door/window assembly (100) having a panel (2) provided with three glass sheets separate by means of channels adapted to define corresponding double glazings (10, 11) and a frame (4) perimetrically fixed to the panel (2). The central sheet (7) of the glass panel (2) is extended beyond the double glazing (10, 11) for a peripheral section (7') that is engaged in a delimited perimeter seat (15) arranged in middle position in the frame (4) in order to support the panel (2). The seat (15) contains a sealing cord in which the peripheral section (7') of the central plate of the panel (2) is embedded.
The frame (4) comprises a central portion (21) provided with a perimeter seat (15) delimited by two parallel longitudinal walls (16) and by a bottom (17) placed to connect the longitudinal walls (16). The perimeter seat (15) contains a structural sealing cord (18) and is engaged by the peripheral section (7') of the central sheet (7) embedded in the aforesaid structural sealing cord (18) in order to support the panel (2). The frame (4) also comprises two lateral portions, of which one is internal (19) and one is external (20), substantially interposed between the peripheral sections (5', 6'), connected together by the central portion (21), and susceptible to mechanically collaborating with connection means (13) in order to angularly join together the uprights and the crosspieces of the frame (4).