Mechanical timepiece

A mechanical timepiece, comprising:

• a hairspring to be elastically deformed so as to cause a balance wheel to perform a forward/reverse rotational motion;
• a permanent magnet which is magnetized into two poles, and is configured to perform a forward/reverse rotational motion along with the forward/reverse rotational motion of the balance wheel;
• a coil in which a counter-electromotive voltage is caused by the forward/reverse rotational motion of the permanent magnet;
• a soft magnetic core including:
• a first end portion to be provided along an outer periphery of the permanent magnet;
• and
• a second end portion which is to be provided along the outer periphery of the permanent magnet, and is to be arranged so as to be opposed to the first end portion through intermediation of the permanent magnet,
• the soft magnetic core being configured to form a magnetic circuit together with the coil;
• and
• a control circuit configured to be driven by an electric power being caused based on the counter-electromotive voltage, and perform rate adjustment based on the counter-electromotive voltage and a normal frequency of a reference signal source;
• wherein the permanent magnet is arranged so that, under a state in which the hairspring is brought to an equilibrium length, a direction of magnetization is directed to the first end portion side or the second end portion side.