To provide a mechanism facilitating incorporation work when incorporating yokes or a coil bobbin incorporated with the yokes by preventing magnets from being attracted to the yokes by a magnetic force.

The magnet drive device includes: magnets 3 and 5; a coil bobbin 11 around which coils 12 and 13 are wound; yokes 7-10 that include yoke bodies 7b-10b supported by the coil bobbin 11, and magnetic pole parts 7a-10a connected to the yoke bodies 7b-10b and disposed facing the magnets 3 and 5; a pressing plate 6 that regulates the thrust-directional positions of the magnets 3 and 5; and a support bottom board 1 in which the magnets 3 and 5, the coil bobbin 11 and the yokes 7-10 are incorporated. The pressing plate 6 has locking portions 6c, 6d and 6e locked to the support bottom board 1, with its holding the magnets 3 and 5 incorporated in the support bottom board 1.