A method for producing small electronic components, electronic circuit boards and small electronic devices

The present invention provides a compact electronic device, small-sized electronic device using the electronic circuit board and a method for producing small electronic devices which prevent the magnetic powder falling ability, adhesiveness external electrodes, withstand voltage characteristics, rust proofing ability, heat resistance, strength after thermal curing properties and excellent molded. The small-sized electronic device comprising: at least a core (100) of the columnar core (110), arranged around the outer circumferential surface side of the pillar-shaped core (110) and the winding (210) formed by winding a winding coil (200 ), and is shaped using a mixed agent containing a surfactant, the magnetic powder and the resin material is at least a portion of the phosphate-based core and follow the shape of the winding coil and the magnetic housing portion (300) of the covering.