To provide a waterproofing member capable of absorbing variation of a setting position of a tile at a joint part of a roof and a building frame body and easy to construct.

A waterproofing member 10 covers a part between an end part of a roof (fox example, a roof panel 71) using a plane roof-tile 60 and a building frame body (for example, a wall panel 72). Thereby, it is furnished with a fixed part 23 fixed on the building frame body 71 and a deforming part 24 extended toward the plane roof-tile 60 from the fixed part 23 and formed free to elastically deform, and the deforming part 24 is furnished with a sealing material 40 to restrain immersion of water in a clearance with the plane roof- tile 60.