A movable assembly used in a cylinder type linear motor is provided which can be manufactured at low cost without requiring a cutting process while preventing its magnetic characteristics from deteriorating. The movable core is constructed of a laminated yoke which is formed of a plurality of electromagnetic steel plates laminated in an axial direction of the first and second direct drive shafts. A plurality of permanent magnets 31 fixed to the laminated yoke 29 are arranged in such a manner that the polarity appearing on the outer surface of the two permanent magnet 31 opposing each other through the laminated yoke 29. The first and second direct drive shafts each have a yoke mounting portion and paired supported portions at both axial ends of the yoke mounting portion. The first and second direct drive shafts are so shaped that the cross section of the yoke mounting portion orthogonal to the axial direction is smaller than that of the supported portions. Each of the electromagnetic steel plates is made up of first and second divided electromagnetic steel plate pieces of the same shape.