PURPOSE: To obtain glass having a coefficient of thermal expansion and low melting point suitable to use for assemble of MIG composite type magnetic head and free from discoloration under high temperature and high moisture by adopting a specific glass composition.

CONSTITUTION: The following composition is adopted as bonding glass 15 for assembling a magnetic core 14 having Fe-Al-Si thin film 23 applied to the face opposite to at least either one gap and a slider 12 made of a non-magnetic ceramic: SiO2 6-11wt.%, B2O3 5-9wt.%, Al2O3 2-5wt.%, PbO 55-70wt.%, Bi2O3 5-15wt.%, TeO2 0-10wt.% and CuO 0.5-2wt.%.