Abstract: Material for semiconductor holder in electron beam writing apparatus is disclosed. The material consists of 1.0-11.0% by weight of iron, 0.2-5.5% by weight of Manganese, 0.0001-1.0% by weight of at least one rare earth element selected from rare earth elements, and remainder of chromium and inevitable impurity, the material having magnetic susceptibility of not more than 5.times.10.sup.-5 emu/G and a thermal expansion coefficient of 0-4.0.times.10.sup.-6 /.degree. C. at a temperature of 0.degree. C.-40.degree. C.

Abstract: Antiferromagnetic chromium base invar-type alloys and a method of producing the same are disclosed. These alloys are produced by adding 0.05-10 wt% of at least one rare earth element to antiferromagnetic chromium base invar-type alloy consisting of 0.5-6 wt% of iron and/or silicon, 1.5-6 wt% of cobalt and/or manganese and remainder of chromium, and then subjecting the resulting alloy ingot to a primary hot working by heating at a temperature of 800.degree.-1200.degree. C, and have a reduction ratio of not less than 60% and a thermal expansion coefficient of not more than 4.times.10.sup.-6 /.degree. C.