<p>A 2 port type isolator in which a first center electrode (35) and a second center electrode (36) are wound around a ferrite (31) which is applied with a DC magnetic field from a permanent magnet and the ferrite (31) is fixed onto a circuit board (20) incorporating a matching circuit element. The ferrite (31) is a rectangular parallelepiped having first and second major surfaces (31a, 31b) parallel with each other wherein the long side length of the major surfaces (31a, 31b) is 1.5-5 times as long as the short side length. The second center electrode (36) is wound around the ferrite (31) by 1-4 turns.</p>
