An impact absorbing member (1, 5) that is configured in its entirety by bending one sheet of a metal plate material, comprising: a fixing plate (10, 50) of an approximate square shape for fixing to a reinforcement (4, 8) for reinforcing a bumper of a vehicle; an impact absorbing part (11, 51) comprising two first side wall plates (111a, 111b, 511 a, 511b) of an approximate square shape, which extend towards one side substantially perpendicularly from two opposite sides of the fixing plate (10, 50), wherein the impact absorbing part (11, 51) is configured in an approximate square tube shape, and two flange plates (12a, 12b, 52a, 52b) for fixing to a frame of a vehicle body, and which extend substantially perpendicularly outwardly at the two first side wall plates (111a, 111b, 511 a, 511 b) from the side thereof opposite of the fixing plate side; characterized in that the impact absorbing member (1, 5) further comprises two second side wall plates (112a, 112b, 512a, 512b) of an approximate square shape, which extend towards the side in the same direction as said one side substantially perpendicularly from the remaining two opposite sides of the fixing plate (10, 50); two bridge plates (13a, 13b, 53a, 53b) that bridge gaps between end parts of the two flange plates (12a, 12b, 52a, 52b), and which extend substantially perpendicularly outwardly at the two second side wall plates (112a, 112b, 512a, 512b) from the side thereof opposite of the fixing plate side, wherein the impact absorbing part (11, 51) comprises joining parts (110, 510) that overlap and join opposite edge parts of the two first side wall plates (111a, 111b, 511 a, 511b) with opposing edge parts of the two second side wall plates (112a, 112b, 512a, 512b) that are respectively adjacent to the opposite edge parts of the two first side wall plates (111a, 111 b, 511 a, 511b), and wherein the end parts of the two flange plates (12a, 12b, 52a, 52b) are joined to end parts of the two bridge plates (13a, 13b, 53a, 53b). a fixing plate (10, 50) of an approximate square shape for fixing to a reinforcement (4, 8) for reinforcing a bumper of a vehicle; an impact absorbing part (11, 51) comprising two first side wall plates (111a, 111b, 511 a, 511b) of an approximate square shape, which extend towards one side substantially perpendicularly from two opposite sides of the fixing plate (10, 50), wherein the impact absorbing part (11, 51) is configured in an approximate square tube shape, and two flange plates (12a, 12b, 52a, 52b) for fixing to a frame of a vehicle body, and which extend substantially perpendicularly outwardly at the two first side wall plates (111a, 111b, 511 a, 511 b) from the side thereof opposite of the fixing plate side; characterized in that the impact absorbing member (1, 5) further comprises two second side wall plates (112a, 112b, 512a, 512b) of an approximate square shape, which extend towards the side in the same direction as said one side substantially perpendicularly from the remaining two opposite sides of the fixing plate (10, 50); two bridge plates (13a, 13b, 53a, 53b) that bridge gaps between end parts of the two flange plates (12a, 12b, 52a, 52b), and which extend substantially perpendicularly outwardly at the two second side wall plates (112a, 112b, 512a, 512b) from the side thereof opposite of the fixing plate side, wherein the impact absorbing part (11, 51) comprises joining parts (110, 510) that overlap and join opposite edge parts of the two first side wall plates (111a, 111b, 511 a, 511b) with opposing edge parts of the two second side wall plates (112a, 112b, 512a, 512b) that are respectively adjacent to the opposite edge parts of the two first side wall plates (111a, 111 b, 511 a, 511b), and wherein the end parts of the two flange plates (12a, 12b, 52a, 52b) are joined to end parts of the two bridge plates (13a, 13b, 53a, 53b).