The present invention provides a hair cosmetic containing a novel block copolymer that continuously imparts smoothness and other characteristics. The hair cosmetic of the present invention contains a block copolymer having a hydrophobic segment and a hydrophilic segment, and the hydrophobic segment has a monomer unit containing at least one monomer selected from the following Formula 1 and Formula 2, hydrophilic The segment has a monomer unit containing the monomer of the following formula 3: In Formula 1, R 1 is hydrogen or methyl, R 2 is hydrogen or fluorine, m is an integer of 1 to 6, and n is an integer of 5 to 15, In Formula 2, R 1 is hydrogen or methyl, R 3 and R 4 are each independently an alkyl group having 1 to 6 carbon atoms, m is an integer of 1 to 6, and p is an integer of 5 to 70, In Formula 3, R 1 is hydrogen or methyl, m is an integer of 1 to 6, and R 5 is independently a functional group that undergoes a cross-linking reaction by hydrolysis.本發明提供一種含有可持續地賦予順滑性等特性之新穎之嵌段共聚物之毛髮化妝料。本發明之毛髮化妝料含有具有疏水性鏈段及親水性鏈段之嵌段共聚物，疏水性鏈段具有包含選自下述式1及式2之至少一種單體之單體單元，親水性鏈段具有包含下述式3之單體之單體單元：式1中，R1為氫或甲基，R2為氫或氟，m為1～6之整數，且n為5～15之整數，式2中，R1為氫或甲基，R3及R4分別獨立為碳數1～6之烷基，m為1～6之整數，且p為5～70之整數，式3中，R1為氫或甲基，m為1～6之整數，且R5分別獨立為水解而發生交聯反應之官能基。
