To facilitate attachment and detachment of a work in both center work operations mainly in a grinding machine.

In the conventional work drive device for a cylindrical grinding machine, a holding pawl plate 9 for a work holds a work by rotating a driving arm 12 engaged with a driving shaft 22a in the holding direction at the initial stage of rotation of the rotary driving device, and subsequently the work drive device is rotated to grind the work. In the device, however, this holding is not released even when the rotary driving device stops. Consequently, a worker manually rotates a rotary driving plate in the reverse direction to release the holding pawl plate and take out the work. According to this invention, the end of the driving arm 12 is provided with a means for energizing in the counter-holding direction instead of the reverse rotating operation of the rotary driving device, and while the driving arm 12 is rotated in the holding direction against the energizing means at the initial stage of rotation of the rotary driving device to hold the work, the holding pawl plate is released by the energizing means when the cylindrical grinding machine stops.