An electromagnetic switch has a contact device having a pair of fixed contacts fixed thereof and maintaining a predetermined interval inside an arc-extinguishing chamber receptacle, and a movable contact disposed to be connectable with the pair of fixed contacts; and an electromagnetic device driving the movable contact. The electromagnetic device has a cylindrical exciting coil, a fixed core passing through center of the exciting coil, a magnetic yoke covering an outer side of the exciting coil, and a movable core facing the fixed core and the magnetic yoke, and armature surfaces of the fixed core and the magnetic yoke are formed on a side of the contact device than the exciting coil.