A fire door comprising at least one door leaf, wherein each door leaf comprises a frame and at least one infill panel retained within the frame, wherein the frame comprises: a first frame member and a second frame member spaced from the first frame member; a glazing bead attached to the second frame member; and at least one retaining device (1,1000) for retaining one of the at least one infill panels between the first frame member and the glazing bead, wherein the retaining device (1,1000) is made of a material having a melting point of at least 1000 °C, and wherein the retaining device (1,1000) comprises: an L-shaped portion located at a first end of the retaining device (1,1000), the L-shaped portion comprising: a first base attached to the first frame member; and a wall extending upwardly from the first base, wherein the wall contacts a first side of the infill panel; a second base located at a second end of the retaining device (1,1000), wherein the second base is attached to the second frame member; a middle portion located intermediate the first end and the second end and adjacent the second base, wherein the middle portion comprises: a raised surface raised with respect to the second base; and a sidewall joining the raised surface to the second base; and at least one leg (40A, 40B) extending from an edge of the raised surface adjacent the sidewall, wherein the at least one leg (40A,40B) is bent upwardly against a second side of the infill panel, and wherein the infill panel is gripped between the wall and the at least one leg (40A,40B), and wherein: the second base includes a protrusion extending from a top surface thereof and spaced from the middle portion; or the retaining device (1,1000) includes an additional piece attached to the top surface of the second base and spaced from the middle portion. a first frame member and a second frame member spaced from the first frame member; a glazing bead attached to the second frame member; and at least one retaining device (1,1000) for retaining one of the at least one infill panels between the first frame member and the glazing bead, wherein the retaining device (1,1000) is made of a material having a melting point of at least 1000 °C, and wherein the retaining device (1,1000) comprises: an L-shaped portion located at a first end of the retaining device (1,1000), the L-shaped portion comprising: a first base attached to the first frame member; and a wall extending upwardly from the first base, wherein the wall contacts a first side of the infill panel; a second base located at a second end of the retaining device (1,1000), wherein the second base is attached to the second frame member; a middle portion located intermediate the first end and the second end and adjacent the second base, wherein the middle portion comprises: a raised surface raised with respect to the second base; and a sidewall joining the raised surface to the second base; and at least one leg (40A, 40B) extending from an edge of the raised surface adjacent the sidewall, wherein the at least one leg (40A,40B) is bent upwardly against a second side of the infill panel, and wherein the infill panel is gripped between the wall and the at least one leg (40A,40B), and an L-shaped portion located at a first end of the retaining device (1,1000), the L-shaped portion comprising: a first base attached to the first frame member; and a wall extending upwardly from the first base, wherein the wall contacts a first side of the infill panel; a first base attached to the first frame member; and a wall extending upwardly from the first base, wherein the wall contacts a first side of the infill panel; a second base located at a second end of the retaining device (1,1000), wherein the second base is attached to the second frame member; a middle portion located intermediate the first end and the second end and adjacent the second base, wherein the middle portion comprises: a raised surface raised with respect to the second base; and a sidewall joining the raised surface to the second base; and at least one leg (40A, 40B) extending from an edge of the raised surface adjacent the sidewall, wherein the at least one leg (40A,40B) is bent upwardly against a second side of the infill panel, and wherein the infill panel is gripped between the wall and the at least one leg (40A,40B), and a raised surface raised with respect to the second base; and a sidewall joining the raised surface to the second base; and at least one leg (40A, 40B) extending from an edge of the raised surface adjacent the sidewall, wherein the at least one leg (40A,40B) is bent upwardly against a second side of the infill panel, and wherein the infill panel is gripped between the wall and the at least one leg (40A,40B), and the second base includes a protrusion extending from a top surface thereof and spaced from the middle portion; or the retaining device (1,1000) includes an additional piece attached to the top surface of the second base and spaced from the middle portion.