Provided is an instrument driving device which is capable of suppressing loss of synchronism caused by vibration and impact etc. The driving device (1) comprises: a magnet (2) which rotates; a driving gear (3) which is coaxial with the magnet (2); an output gear (5) which is driven by the magnet (2); a needle pointer shaft (6) which has a needle pointer (14) mounted thereon and also rotatably supports the output gear (5); a transmission gear (4) which transmits rotation of the driving gear (3) to the output gear (5); and a case (12) which accommodates parts of the magnet (2), the driving gear (3), the output gear (5), the transmission gear (4), and the needle pointer shaft (6), wherein a stopper (16) and a bearing part (12c) which rotatably supports the needle pointer shaft (6) are provided in the case (12), a protrusion (15) which makes contact with the stopper (16) is formed in the output gear (5), a contact point (12d) with which the needle pointer shaft (6) makes contact is formed in the bearing part (12c), and the end section (16b) at the protrusion (15) side of the stopper (16) is in the same position as the contact point (12d) in the axial direction of the needle pointer shaft (6).