<p>[PROBLEMS] To reduce a reactor core shape so as to reduce an entire reactor size and lower a cost while improving DC superimposition of a high current value. [MEANS FOR SOLVING PROBLEMS] In a reactor core (109), cross-sectional areas W1a*Ha of two magnetic blocks (103a) constituting a non-winding portion where no line is wound are reduced by about 24% to 33% as compared to cross-sectional areas Wb*Hb in the direction orthogonally intersecting magnetic paths of magnetic blocks (3b) constituting a winding portion.</p>
