A block copolymer that comprises a first block and a second block different from the first block and that exhibits, in a X ray diffraction, at least one peak of which a full width at half maximum is from 0.2 nm -1 to 1.5 nm -1 at a range of scattering vector (q) from 0.5 nm -1 to 10 nm -1, wherein the first block is represented by Formula 1 below: wherein R is hydrogen or an alkyl group having 1 to 4 carbon atoms; X is a carbonyl group, -C(=O)-X 1 - or -X 1 -C(=O)-, wherein X 1 is an oxygen atom or a sulfur atom; and Y is a monovalent substituent comprising an aromatic structure having 6 to 12 carbon atoms to which a chain having 10 to 20 chain-forming atoms is linked via a linker that is an oxygen atom, a sulfur atom, -NR 1 - or a carbonyl group, wherein R 1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, and wherein the X ray diffraction pattern is evaluated by measuring the scattering intensity according to the scattering vector (q) by passing X rays through a sample in a 4C beam line of the Pohang Light Source, the sample being a powder obtained from the block copolymer to which any specific pre-treatment was not performed by purifying it so as to remove impurities therefrom; during the X ray diffraction pattern analysis, an X ray having a vertical size of 0.023 mm and a horizontal size of 0.3 mm is used, and a measuring device is used as the detector; a 2D diffraction pattern scattered from the sample is obtained as an image, and information such as the scattering vectors and the FWHMs is obtained by analyzing the obtained diffraction pattern by numerical analysis using the least square technique, wherein the analysis is performed by the origin program in which a position at which the X ray diffraction pattern has the lowest intensity is the baseline and the lowest intensity is converted to zero, and then Guassian fitting is performed with respect to the profile of peaks in the X ray diffraction pattern, and then the scattering vector (q) and the FWHM is obtained from the result of the Gaussian fitting, wherein R square of the Guassian fitting is set to be 0.96 or more. wherein R is hydrogen or an alkyl group having 1 to 4 carbon atoms; X is a carbonyl group, -C(=O)-X 1 - or -X 1 -C(=O)-, wherein X 1 is an oxygen atom or a sulfur atom; and Y is a monovalent substituent comprising an aromatic structure having 6 to 12 carbon atoms to which a chain having 10 to 20 chain-forming atoms is linked via a linker that is an oxygen atom, a sulfur atom, -NR 1 - or a carbonyl group, wherein R 1 is hydrogen or an alkyl group having 1 to 4 carbon atoms, and wherein the X ray diffraction pattern is evaluated by measuring the scattering intensity according to the scattering vector (q) by passing X rays through a sample in a 4C beam line of the Pohang Light Source, the sample being a powder obtained from the block copolymer to which any specific pre-treatment was not performed by purifying it so as to remove impurities therefrom; during the X ray diffraction pattern analysis, an X ray having a vertical size of 0.023 mm and a horizontal size of 0.3 mm is used, and a measuring device is used as the detector; a 2D diffraction pattern scattered from the sample is obtained as an image, and information such as the scattering vectors and the FWHMs is obtained by analyzing the obtained diffraction pattern by numerical analysis using the least square technique, wherein the analysis is performed by the origin program in which a position at which the X ray diffraction pattern has the lowest intensity is the baseline and the lowest intensity is converted to zero, and then Guassian fitting is performed with respect to the profile of peaks in the X ray diffraction pattern, and then the scattering vector (q) and the FWHM is obtained from the result of the Gaussian fitting, wherein R square of the Guassian fitting is set to be 0.96 or more.