Abstract: A piezoelectrically driving device comprises a driving part including paired opposing pole parts substantially square shaped in section, piezoelectric elements provided at least to two adjacent faces of each of the opposing pole parts for causing them to flectionally vibrate resonantly in response to an applied high frequency voltage, and a contact member contactable with one face of each of the opposing pole parts for movement relative thereto or vice versa due to the vibration, any energy loss upon which movement is thereby remarkable restrained and a mechanical driving force can be obtained highly efficiently.