Disclosed is a scanning optical module, which includes a light source, a rotatable multifaceted mirror adapted to scanningly deflect a scanning beam emitted from the light source, in a given direction, a driving device adapted to drivingly rotate the rotatable multifaceted mirror through a shaft thereof, a plate-shaped member formed with a driving device-mounting portion mounting thereto the driving device in such a manner as to absorb heat generated in the shaft, an air blower adapted to generate an airstream, and an airstream passage-defining member adapted to direct the airstream from the air blower, toward the driving device-mounting portion of the plate-shaped member.