One end of a case member is provided with a bent portion, so that when a connector member is inserted through an opening in the other end of the case member, the connector member is positioned by the bent portion. After the connector member has been inserted, all of the various solenoid component members are successively inserted through the opening in the other end of the case member. After a bracket plate is attached, a valve section is attached, and crimping is effected using a crimping projection prepared at one end of a valve sleeve, thereby making it possible to improve assembly operation and to reduce the burden on each of the component members during assembling operation.