Abstract: This invention provides a magnetic head device to be incorporated in a hard disc drive device which can minimize the fluctuations in the height of a floating head slider between the outer periphery and inner periphery of a magnetic disc and which has stable floating characteristics over the whole recording area thereof. The magnetic head device includes a head arm which is attached within a hard disc drive device in a rotatable/swingable manner and a head slider fixed on an end of a suspension member extending from the head arm, wherein the distance between the rotational center of the head arm to the center of the head slider and the position of the center of the rotation of the head arm are so determined to satisfy the relation, −0.1≦(D−L)≦0.6 W−4.