Abstract: A magnetic screw driving device 9 is for rotating a helical magnet shaft 11, that is axially supported on a housing 17, through a drive shaft 13 connected to a motor. The drive shaft 13 and the helical magnet shaft 11 are respectively provided with cylindrical collars 19 through which the drive shaft 13 and the helical magnet shaft 11 are inserted and which are mounted airtightly and oil seals 20 mounted to the housing 17 to come in sliding contact with surfaces of the collars 19 to thereby seal a lubricant Gr in the housing 17. As a result, it is possible to provide a magnetic screw driving device which contributes to reduction in maintenance cost and running cost.