A light scanning device, including: a rotating multifaceted mirror that deflects a light beam from a light source section and scans a scanned face using the light beam; a lens for focusing onto the scanned face the light beam that has been deflected and scanned by the rotating multifaceted mirror; a motor for driving rotation of the rotating multifaceted mirror, the motor having a rotating shaft to which the rotating multifaceted mirror is secured; and a housing for housing, inside thereof, the lens, the rotating multifaceted mirror, and the motor, the housing having a bearing section for rotatably supporting the rotating shaft of the motor, characterized in that the bearing section comprises: a first fitting section of circular shape having a predetermined length in the axial direction of the rotating shaft, and fitting with the outside peripheral face (41 a) of the rotating shaft about the entire outside peripheral face thereof, rotatably supporting the entire outside peripheral face of the rotating shaft; a second fitting section formed to the outer edge side of the first fitting section and extending in the axial direction of the rotating shaft towards an outer edge of the housing from the peripheral edge of the first fitting section, and having an arcuate face formed to identical radial length as the first fitting section; the second fitting section rotatably supporting part of the outside peripheral surface of the rotating shaft; and a heat-radiating section adjacent to the second fitting section in the circumferential direction, the heat-radiating section formed by a slot cut out in a predetermined direction, and adapted to expose a portion of the outside peripheral face of the rotating shaft through the housing. a rotating multifaceted mirror that deflects a light beam from a light source section and scans a scanned face using the light beam; a lens for focusing onto the scanned face the light beam that has been deflected and scanned by the rotating multifaceted mirror; a motor for driving rotation of the rotating multifaceted mirror, the motor having a rotating shaft to which the rotating multifaceted mirror is secured; and a housing for housing, inside thereof, the lens, the rotating multifaceted mirror, and the motor, the housing having a bearing section for rotatably supporting the rotating shaft of the motor, characterized in that the bearing section comprises: a first fitting section of circular shape having a predetermined length in the axial direction of the rotating shaft, and fitting with the outside peripheral face (41 a) of the rotating shaft about the entire outside peripheral face thereof, rotatably supporting the entire outside peripheral face of the rotating shaft; a second fitting section formed to the outer edge side of the first fitting section and extending in the axial direction of the rotating shaft towards an outer edge of the housing from the peripheral edge of the first fitting section, and having an arcuate face formed to identical radial length as the first fitting section; the second fitting section rotatably supporting part of the outside peripheral surface of the rotating shaft; and a heat-radiating section adjacent to the second fitting section in the circumferential direction, the heat-radiating section formed by a slot cut out in a predetermined direction, and adapted to expose a portion of the outside peripheral face of the rotating shaft through the housing. a first fitting section of circular shape having a predetermined length in the axial direction of the rotating shaft, and fitting with the outside peripheral face (41 a) of the rotating shaft about the entire outside peripheral face thereof, rotatably supporting the entire outside peripheral face of the rotating shaft; a second fitting section formed to the outer edge side of the first fitting section and extending in the axial direction of the rotating shaft towards an outer edge of the housing from the peripheral edge of the first fitting section, and having an arcuate face formed to identical radial length as the first fitting section; the second fitting section rotatably supporting part of the outside peripheral surface of the rotating shaft; and a heat-radiating section adjacent to the second fitting section in the circumferential direction, the heat-radiating section formed by a slot cut out in a predetermined direction, and adapted to expose a portion of the outside peripheral face of the rotating shaft through the housing.