To sensually, correctly and surely understand the stroke limit in a screw-type jack device by an operator of a threaded shaft.

A screw-type jack device comprises a threaded shaft 17 one end part of which is supported so as to be rotatable in one of two members which are relatively movable in an advancing/retracting manner, and a female screw body 18 provided on the other member so as to be screw-fitted to the threaded shaft 17. The two members are relatively advanced/retracted to/from each other. A projecting part 42 in the radial direction is provided on a free end of the threaded shaft 17, and a stop part 46a which is abutted on a side 42a in the rotational direction of the projecting part 42 at least at one stroke end of the relative advancing/retracting movement of two members, and prevents the rotation of the threaded shaft 17, is provided on a member provided with the female screw body 18.