The invention relates to a method of controlling the run-up of an electronically commutated electric motor (1) to drive a tool. A rotor (7) rotates in the rotating field (21) of the stator (2). The field windings (3, 4, 5) alternately have a supply voltage applied thereto via an actuation unit (10) in order to obtain an advancing motor rotating field. For advancing the rotating field in the rotational direction (29) of the rotor (7), the inductance of the arrangement of the field coils (3, 4, 5), which is ascertained via a changing measuring current (IM), is evaluated and the advancement is carried out upon reaching a maximum.