To provide a structure for installing a controller for a one-spindle drive-type motor of a spinning machine, capable of improving workability in maintenance without giving undesirable influence on operations for the centering of spindles.

A one-spindle drive-type motor 2 is fixed through a nut 5 coupled with a bolster 3 supporting a spindle 4 to a spindle rail 1 in a tightened state. An attaching portion 1a is formed so as to extend vertically and upwardly in a united state in front of the rail 1. A case 6 for a control unit is fixed on the portion 1a through a screw 7 and is equipped with a control circuit board 8 for controlling the motor 2 and a switch 9 for instructing a start and stop of each motor 2 individually. An input line 14 for the motor 2 and the one end of a control input line 16 the other end of which is coupled with a bus bar 12 extended from the downward portion 1b of the rail 1 are coupled with a connector 15. The connector 15 is coupled with a connector 11 installed on the board 8.