To provide a movable iron core and a solenoid valve including a valve body having no shrinkage or foam on the surface and no void inside.

A movable iron core 10 is used by moving whike facing fixed iron core 5 in order to open/close a fluid channel in a solenoid valve 1 having the fixed iron core 5, and is provided with a movable iron core body 13 having a recessed valve body holding part 12 with a prescribed depth at least at one end and an elastic valve body 11 freely fitted so as not to fall down in the valve body holding part 12. The elastic valve body 11 is not vulcanized and not attached on the inner surface of the valve body holding part 12.