The invention relates to a novel casement window. The technical scheme is as follows: the casement window comprises a window frame and at least one window sash mounted on the window frame, multiple vertical shafts which are placed on left and right sides of the at least one window sash and can slide vertically are mounted on the window frame, and multiple vertical shafts placed on the same side ofthe at least one window sash are coaxially arranged; multiple vertical insertion holes which are in one-to-one coaxial correspondence to the vertical shafts are formed in the at least one window sash, when the vertical shafts slide to be inserted into the insertion holes, the at least one window sash and the window frame are hinged together, and when the vertical shafts slide out of the insertionholes, the at least one window sash and the window frame are separated. Opening of the at least one window sash at different angles is realized by controlling the different vertical shafts, the goodventilation requirement can be met, and indoor sanitary pollution and potential safety risks can be avoided.