Low thermal expansion ceramic and member for exposure system

A low-thermal-expansion, rigid and wear-resistant ceramic is provided. The low-thermal-expansion ceramic of the invention includes 60 vol % to 99.9 vol % of at least one selected from the group consisting of cordierite, spodumene and eucryptite and 0.1 vol % to 40 vol % of at least one selected from the group consisting of carbides, nitrides, borides and silicides of group 4a elements, group 5a elements and group 6a elements, and boron carbide. The ceramic has a porosity of 0.5 % or less and a thermal expansion coefficient, at 10° C. to 40° C., of 1.5×10 −6 /° C. or less.