Reducing gear and starter device of an internal combustion engine

A starter device (1) of an internal combustion engine, the starter device having an electric motor (2) by means of which the internal combustion engine can be started, the starter device further including a reducing gear (3) provided between the electric motor (2) and the internal combustion engine, the reducing gear operable as a speed-reducing coupling of a drive shaft and a driven shaft (5, 7), by means of at least two gearwheels (11) which engage with one another, characterized in that the gearwheels (11) have straight-cut toothing and the toothing (30) is extra deep toothing (31), wherein the reducing gear (3) is a planetary gear mechanism (4), with a sun gear (8), a ring gear (9) and at least one planet gear (10), which is arranged between the sun gear (8) and the ring gear (9) and engages therewith, and wherein the extra deep toothing (31) has an effective minimum profile coverage of at least two between the sun gear (8) and the planet gear (10).