To provide a driving device detecting the position of a driven member in a simple configuration, having a reduced number of components, using a compact unit, and efficiently assembled.

On a frame 11, a drive shaft 12 is axially movably supported, a guide shaft 13 is supported parallel to the drive shaft 12, and the driven member 20 is supported so as to be frictionally engaged with the drive shaft 12 and guide shaft 13 via spring members 16 and 18. One end of an electric-mechanical conversion element 21 is fixed to the frame 11 in its expansion/contraction direction, and the other end is connected to the drive shaft 12 so as to be integrated into one axis. The electric-mechanical conversion element 21 is expanded/contracted to move the driven member 20. At least the external surface of the drive shaft 12 and guide shaft 13 are conductive. The spring members 16 and 18 in slide contact with the external surface of each shaft are electrically connected on the driven member 20. The drive shaft 12, guide shaft 13, and driven member 20 constitutes a closed circuit. The position of the driven member 20 is detected by a position detector 23 connected to the end 12a of the drive shaft 12 and the end 13a of the guide shaft 13.