Elevator, which includes a guide rail line, which includes a plurality of consecutive guide rails, which are supported on the building with guide rail brackets fixed to the building, which guide rail brackets comprise a frame, a mounting base and structure for pressing the guide rail against the mounting base, which guide rail bracket essentially prevents at its point lateral movement of the guide rail in relation to the fixing point of the guide rail bracket and permits longitudinal movement of the guide rail in relation to the fixing point of the guide rail bracket. The aforementioned mounting base is fixed to the frame of the guide rail bracket movably in the longitudinal direction of the guide rail.