A method of manufacturing a micro flux gate sensor that has a good electrical connection and can be easily manufactured includes operations of forming a metal pattern, forming a first insulation layer to cover the metal pattern and forming viaholes to expose a certain portion of the metal pattern, applying an electrical signal through the metal pattern and plating the viaholes with a metal material to form a connection portion, forming a magnetic core on an upper portion of the first insulation layer, forming a second insulation layer to cover the magnetic core and forming an upper coil portion electrically connected to the connection portion to form the excitation coil and the magnetic field detecting coil, forming a third insulation layer to cover the upper coil portion, and removing a certain portion of the metal pattern to leave only the lower coil portion of the metal pattern.