Abstract: 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 (2) with permanently magnetic poles (8,9), a stator (3,4,5) and a coil (6), as well as a gear driven by the action of the step motor for driving the clock hands, the stator being constructed from two stator parts (3,4) situated on either side of the rotor and a yoke (5), connecting these two parts and extending through said coil. The poles (8,9) are situated in a same cross section plane, perpendicular to the rotation axis of the rotor, and form a ring-shaped layer (14) which is thin in radial direction. According to a preferred embodiment the rotor is at the radial inner side of the poles provided with an uninterrupted round-going ring-shaped portion (7) of soft-magnetic material.