PURPOSE: To improve ignition, flame propagation and combustion properties, by passing a liquid fuel oil through a focusing field in a magnetic field of the same polarity of permanent magnets, and applying an intermittent electromagnetic field and intermittent high-voltage electric field to the focusing field.

CONSTITUTION: A liquid fuel oil is fed to an injection pump and spray burner in an internal-combustion engine, boiler, etc. In the process, the liquid fuel oil is passed through a focusing field in a magnetic field of the same polarity of permanent magnets, and an induction current produced by the electric field effect of an intermittent high-voltage current generated in an ignition coil is used to apply an intermittent electromagnetic field and intermittent high-voltage electric field to the focusing field in the magnetic field of the same polarity of the permanent magnets.