Timepiece having a multipolar rotor

Electro-mechanical timepiece, comprising a circuit for generating electric pulses that appear at suitable points of time, a stepper motor controlled by said pulses and comprising a rotor with permanently magnetic poles, a stator and a coil, as well as a gear driven by the action of the stepper motor for driving the clock hands, the stator being constructed from two stator parts located in the same plane as and situated laterally on either side of the rotor, and a yoke, connecting these two parts and extending through said coil, wherein the poles are all situated in a single cross section plane, perpendicular to a rotational axis of the rotor, and form a ringshaped layer which is thin in a radial direction wherein at the radial inner side of the poles, the rotor includes an uninterrupted circular portion made of a soft-magnetic material, said material providing a path for a magnetic flux emanating from the rotor as well as a magnetic flux emanating from the stator.