A steering apparatus comprising: a steering shaft connected to a steering member; a hollow steering column rotatably supporting the steering shaft and being pivotable about a tilt center; a first bracket including a first side plate and fixed to a vehicle body; a second bracket that includes a second side plate facing the first side plate and is fixed to the steering column; and a lock mechanism that includes a fastening shaft passed through a tilt elongate hole as a first through hole of the first side plate and a second through hole of the second side plate, an operation lever capable of rotating together with the fastening shaft, and a fastening mechanism that includes a fastening member (33, 38) and fastens the first side plate to the second side plate by the fastening member (33, 38) upon a rotation operation of the operation lever in a locking direction; wherein: the fastening mechanism further includes a first tooth row that is provided in close vicinity of the tilt elongate hole of the first side plate and is formed of parallel teeth arranged in a tilt direction, the fastening member (33, 38) includes a fastening plate (36, 40) for fastening the first side plate, a second tooth row that is provided on the fastening plate (36, 40) and is formed of parallel teeth meshed with the first tooth row, and a boss (37, 41) that extends from the fastening plate (36, 40), is passed through the tilt elongate hole with a predetermined play therebetween to be restrained from rotating, and is guided along the tilt elongate hole at the time of tilt adjustment, the tilt elongate hole includes a first end located on a tilt direction upper side and a second end located on a tilt direction lower side, characterized in that a width of the first end of the tilt elongate hole is different from a width of the second end of the tilt elongate hole. a steering shaft connected to a steering member; a hollow steering column rotatably supporting the steering shaft and being pivotable about a tilt center; a first bracket including a first side plate and fixed to a vehicle body; a second bracket that includes a second side plate facing the first side plate and is fixed to the steering column; and a lock mechanism that includes a fastening shaft passed through a tilt elongate hole as a first through hole of the first side plate and a second through hole of the second side plate, an operation lever capable of rotating together with the fastening shaft, and a fastening mechanism that includes a fastening member (33, 38) and fastens the first side plate to the second side plate by the fastening member (33, 38) upon a rotation operation of the operation lever in a locking direction; wherein: the fastening mechanism further includes a first tooth row that is provided in close vicinity of the tilt elongate hole of the first side plate and is formed of parallel teeth arranged in a tilt direction, the fastening member (33, 38) includes a fastening plate (36, 40) for fastening the first side plate, a second tooth row that is provided on the fastening plate (36, 40) and is formed of parallel teeth meshed with the first tooth row, and a boss (37, 41) that extends from the fastening plate (36, 40), is passed through the tilt elongate hole with a predetermined play therebetween to be restrained from rotating, and is guided along the tilt elongate hole at the time of tilt adjustment, the tilt elongate hole includes a first end located on a tilt direction upper side and a second end located on a tilt direction lower side, characterized in that a width of the first end of the tilt elongate hole is different from a width of the second end of the tilt elongate hole. the fastening mechanism further includes a first tooth row that is provided in close vicinity of the tilt elongate hole of the first side plate and is formed of parallel teeth arranged in a tilt direction, the fastening member (33, 38) includes a fastening plate (36, 40) for fastening the first side plate, a second tooth row that is provided on the fastening plate (36, 40) and is formed of parallel teeth meshed with the first tooth row, and a boss (37, 41) that extends from the fastening plate (36, 40), is passed through the tilt elongate hole with a predetermined play therebetween to be restrained from rotating, and is guided along the tilt elongate hole at the time of tilt adjustment, the tilt elongate hole includes a first end located on a tilt direction upper side and a second end located on a tilt direction lower side, characterized in that a width of the first end of the tilt elongate hole is different from a width of the second end of the tilt elongate hole.