To provide a solenoid having a higher corrosion resistivity with a reduced cost, compared with conventional solenoids.

The solenoid is provided with a case member 101 composed of a magnetic body for storing a coil member 102 therein; a sleeve 103 arranged inside the coil member 102; a fixed iron core 104 and a movable iron core 105 arranged inside the sleeve 103; a cylindrical member 108 which is arranged outside of a section in the vicinity of one end of the sleeve 103 in the radial direction, connected to one end section of the case member 101 and is composed of a magnetic body facing the fixed iron core 104 or the movable iron core 105; a seal member 109 arranged on the external circumference of the cylindrical member 108; and a resin member 110 which makes close contact with the cylindrical member 108 to close the end section of the cylindrical member 108 on a side separated from the case member 101 and to cover the one end of the sleeve 103.