A hard film formed by an arc-discharge ion-plating method, having a composition comprising metal components represented by Al.sub.xCr.sub.1-x-ySi.sub.y, wherein x and y are respectively atomic ratios meeting 0.45.ltoreq.x.ltoreq.0.75, 0.ltoreq.y.ltoreq.0.35, and 0.5.ltoreq.x+y<1, and non-metal components represented by N.sub.1-.alpha.-.beta.-.gamma.B.sub..alpha.C.sub..beta.O.sub..gamma., wherein .alpha.,.beta. and .gamma. are respectively atomic ratios meeting 0.ltoreq..alpha..ltoreq.0.15, 0.ltoreq..beta..ltoreq.0.35, and 0.003.ltoreq..gamma..ltoreq.0.25, the hard film having an NaCl-type crystal structure, with a half width of 2.theta. at an X-ray diffraction peak corresponding to a (111) face or a (200) face being 0.5 2.0.degree., and the hard film containing oxygen more in grain boundaries than in crystal grains.