A sensing probe for measuring device performance electrically at a delivery inspection is disclosed. The probe comprises a plunger, a barrel and a coil spring. The plunger provides a groove in an outer surface thereof, while, the inner surface of the barrel provides a projection. The groove comprises a plurality of unit patterns including a front groove and a rear groove. The projection slides in the front groove as the plunger is pulled into the barrel, while, it slides in the rear groove as the plunger is pushed out from the barrel. Moreover, the plunger rotates in the barrel as the projection slides in the front and rear grooves, which makes an area of the plunger coming in contact with the barrel always fresh and lowers the contact resistance between them.