A starter with a reduction mechanism provided between a motor and a pinion clutch includes a pinion shaft mechanically coupled to the inner portion periphery of a clutch inner of the pinion clutch in such a manner as to be movable in the axial direction thereof, and a pinion provided at one end of the pinion shaft. The starter further, includes first helical splines provided between the clutch inner portion of the pinion clutch and the pinion shaft, and second helical splines provided at one end of the pinion shaft such that the pinion shaft is mechanically coupled to the pinion therethrough.
