To provide a solenoid and a starter with high reliability for reducing the size and weight of a magnetic switch while maintaining suction force of the magnet switch, and securely operating even at low voltages.

The solenoid for structuring the magnet switch 3 of the starter 10 comprises an exciting coil 3f for generating magnetic force by energization, a plunger 3a as a movable core which is a movable member for structuring a part of a magnetic circuit, and a fixed core 3j oppositely arranged to the movable core and structuring a part of the magnetic circuit. The plunger 3a as the movable core comprises a first plunger 31a divided into a plurality of pieces concentrically, and a second plunger 32a. After the second plunger 32a is sucked, the first plunger 31a is sucked.