PURPOSE: To provide a magnetic head which realizes high density recording by realizing a magnetic thin film of CoHfTa which ensures high saturation flux density, a little negative magnetic distortion and high heat resistance characteristic.

CONSTITUTION: In a Co-Hf-Ta alloy having the composition range where Co is 86 to 88 atomic %, Hf is 3 to 6 atomic %, and Ta is 6 to 9 atomic %, a magnetic thin film having high magnetic flux density of 1.1 T or more, magnctostriction of -2×10-6 to 0 and heat resistance characteristic of 425°C can be formed.