A workpiece holding device includes a main body having a groove and a bearing plate configured to receive a workpiece; an elastic member mounted in the groove at an angle relative to the bearing plate, and having an engaging portion protruding beyond the groove; and a resisting member having an inclined surface received in the groove. The inclined surface can abut the elastic member. When the resisting member rises it forces the engaging portion of the elastic member to move toward the bearing plate, thus securing the workpiece when present. When the resisting member lowers the elasticity of the engaging portion causes it to move away from the bearing plate, thus releasing the workpiece when present.