A starter for an internal combustion engine has no radial protrusion of an auxiliary switch in a shape projected along an axial direction thereof, thus improving the degree of freedom in mounting the starter on the engine. An axially extending electromagnetic switch is mounted on a motor for turning it on and off. An auxiliary switch extends in an axial direction of the motor and is mounted thereon for operating the electromagnetic switch by means of an operation of a key switch. A pinion gear can be placed into or out of engagement with a ring gear of the engine so as to be driven by the motor. The motor has a bracket with a radially extending flange, through which the starter is mounted on the engine. The auxiliary switch is arranged at an inner side of a common tangent line between outer peripheries of the electromagnetic switch and the flange.