The present invention relates to a fire door. The fire door includes: a front panel member; a rear panel member; first and second coupling units coupling upper and lower parts of the front and rear panel members with each other; and third and fourth coupling units coupling left and right parts of the front and rear panel members with each other. The third and fourth coupling units include: a first transverse coupling part including a first transverse bent part extended from left and right edges of the front panel member to the rear panel member, and a second transverse bent part bent inward from the first transverse bent part to be extended; a second transverse coupling part including a third transverse bent part extended from left and right edges of the rear panel member to the front panel member, and a second transverse bent part bent from the third transverse bent part to be extended in a direction parallel with the front panel member; and an inner transverse frame including a first transverse part extended between the front panel member and the second transverse bent part to be opposed to the second transverse bent part, a second transverse part bent on a position, corresponding to an end of the second transverse bent part, of the first transverse part, to be extended side by side with the first transverse bent part, a third transverse part extended from an end of the second transverse part side by side with the front panel member, a fourth transverse part bent from an end of the third transverse part to be extended side by side with the third transverse part, a fifth transverse part extended from an end of the fourth transverse part side by side with an extending direction of the rear panel member, a sixth transverse part extended from an end of the fifth transverse part side by side with the fourth transverse part, and a seventh transverse part placed at an end of the sixth transverse part side by side with the third transverse bent part to be coupled with the third transverse bent part through a coupling member. Therefore, the present invention is capable of improving manufacturability and enhancing heat/smoke insulation performance.

본 발명은 방화문에 관한 것으로서, 전면패널부재와, 후면패널부재와, 전면패널부재와 후면패널부재의 상부 및 하부측을 상호 결합하는 제1 및 제2결합유닛과, 전면패널부재와 후면패널부재의 좌측부와 우측부를 상호 결합하는 제3 및 제4결합유닛를 구비하며, 제3 및 제4결합유닛은 전면패널부재의 좌우측 가장자리로부터 후면패널부재 측으로 연장된 제1횡절곡부와, 제1횡절곡부에서 내측으로 절곡되어 연장된 제2횡절곡부를 구비한 제1횡결합부와, 후면패널부재의 좌우측 가장자리로부터 전면패널부재 측으로 절곡되는 제3횡절곡부와, 제3횡절곡부로부터 절곡되어 전면패널부재와 나란한 방향으로 연장된 제4횡절곡부를 갖는 제2횡결합부와, 전면패널부재와 제2횡절곡부 사이에서 제2횡절곡부와 대향되게 연장된 제1횡부분과, 제1횡부분의 제2횡절곡부의 종단과 대응되는 위치에서 절곡되어 제1횡절곡부와 나란하게 연장된 제2횡부분과, 제2횡부분의 종단에서 전면패널부재와 나란하게 연장된 제3횡부분과, 제3횡부분의 종단에서 절곡되어 제3횡부분과 나란하게 연장된 제4횡부분과, 제4횡부분의 종단에서 후면패널부재의 연장방향과 나란하게 연장된 제5횡부분과, 제5횡부분의 종단에서 제4횡부분과 나란하게 연장된 제6횡부분과, 제6횡부분의 종단에서 제3횡절곡부와 나란하게 배치되어 제3횡절곡부와 체결부재에 결합되는 제7횡부분을 갖는 이너횡프레임을 구비한다.