An optical element, comprising: a sheet-like molded body comprising an optical functional pattern in a surface thereof, wherein the sheet-like molded body is made of a thermoplastic polymer composite including an acrylic block copolymer and an acrylic resin, wherein the acrylic block copolymer is an acrylic block copolymer comprising in each molecule, at least a structure in which a polymer block mainly composed of a methacrylic ester unit is bonded to each end of a polymer block mainly composed of an acrylic ester unit, the acrylic block copolymer having a weight-average molecular weight of 10,000 to 100,000, wherein the acrylic block copolymer comprises an acrylic block copolymer comprising the copolymer block in an amount of 40% by mass to 80% by mass, and an acrylic block copolymer comprising the copolymer block in an amount of 10% by mass to 40% by mass; wherein the acrylic resin is mainly composed of a methacrylic ester unit; and wherein the mass ratio ( /) of the acrylic block copolymer to the acrylic resin is in a range from 97/3 to 10/90, wherein the sheet-like molded body has a tensile elastic modulus of 1500 MPa or less, a linear expansion coefficient of 7.0×10 -5 /oC or less, an average transmittance of 85% or more at least in a visible wavelength range at a thickness of 400 μm, and a haze value of 1.0% or less, and when the optical element is irradiated by rays of light including ultraviolet rays with an illuminance of 1 kW/m 2 for 600 hours using a metal halide lamp, an average transmittance of the optical element is reduced by 2% or less at least in a wavelength range from 350 nm to 600 nm, characterized in that the optical element further comprising a transparent substrate; wherein an other surface of the sheet-like molded body than the one comprising the optical functional pattern is bonded to the transparent substrate; and wherein the transparent substrate has a thickness to an area of the transparent substrate of 5 mm or less to an area of 1 m 2, and the sheet-like molded body has a thickness of one fifteenth or more of the thickness of the transparent substrate. a sheet-like molded body comprising an optical functional pattern in a surface thereof, wherein the sheet-like molded body is made of a thermoplastic polymer composite including an acrylic block copolymer and an acrylic resin, wherein the acrylic block copolymer is an acrylic block copolymer comprising in each molecule, at least a structure in which a polymer block mainly composed of a methacrylic ester unit is bonded to each end of a polymer block mainly composed of an acrylic ester unit, the acrylic block copolymer having a weight-average molecular weight of 10,000 to 100,000, wherein the acrylic block copolymer comprises an acrylic block copolymer comprising the copolymer block in an amount of 40% by mass to 80% by mass, and an acrylic block copolymer comprising the copolymer block in an amount of 10% by mass to 40% by mass; wherein the acrylic resin is mainly composed of a methacrylic ester unit; and wherein the mass ratio ( /) of the acrylic block copolymer to the acrylic resin is in a range from 97/3 to 10/90, wherein the sheet-like molded body has a tensile elastic modulus of 1500 MPa or less, a linear expansion coefficient of 7.0×10 -5 /oC or less, an average transmittance of 85% or more at least in a visible wavelength range at a thickness of 400 μm, and a haze value of 1.0% or less, and when the optical element is irradiated by rays of light including ultraviolet rays with an illuminance of 1 kW/m 2 for 600 hours using a metal halide lamp, an average transmittance of the optical element is reduced by 2% or less at least in a wavelength range from 350 nm to 600 nm, characterized in that the optical element further comprising a transparent substrate; wherein an other surface of the sheet-like molded body than the one comprising the optical functional pattern is bonded to the transparent substrate; and wherein the transparent substrate has a thickness to an area of the transparent substrate of 5 mm or less to an area of 1 m 2, and the sheet-like molded body has a thickness of one fifteenth or more of the thickness of the transparent substrate.