PURPOSE: To provide an integrally formed ball screw type direct-guiding unit enabling high speed and accuracy location while omitting a ball circulating tube to reduce the number of parts.

CONSTITUTION: Ball returning paths 14 in ball rolling grooves 2, 13 of a straight line guide system and ball returning paths 24 in a screw groove 8 of a ball screw system are both provided in the thick part of a nut body 10A. In front and rear end caps 12 of the nut body 10A are provided both a bent path 15 affording communication between the ball 1-A are provided both a bent path 15 affording communication between the ball rolling grooves 2, 13 and ball returning paths 14 and a bent path 26 affording communication between the ball screw groove 8 and ball returning path 24, and a spiral projection 31 crossing the bent path 26 to guide balls in the ball screw groove is provided to enlarge a lead by employing a multiple thread screw while omitting a ball circulating tube for the purpose.