Since a pinion gear unit which rotates according to the rotation of an output rotation shaft driven by the motor unit, a pushing mechanism which moves the pinion gear unit towards an engagement location of the pinion gear and an engine starting gear, and a bracket which includes a bracket main body unit which supports the motor unit and the pushing mechanism and a nose unit which extends from the bracket main body unit to a side opposite to the motor unit and rotatably bears a tip portion of the output rotation shaft on a side opposite to the motor unit, and which is attached to an engine side are included, a first stopper unit which restricts the movement of the rotation member to the direction of the engine starting gear is provided on the output rotation shaft, a second stopper unit which restricts the movement of the pinion gears to the direction of the engine starting gear by pushing and biasing of the elastic member is provided on the rotation member, and positioning the first stopper unit is positioned on a side opposite to the engine starting gear with respect to the second stopper unit, it is possible to shorten the shaft length of the rotation member and to shorten the entire length of the engine starting device.