Two-function tilting and turning roof window is provided on both sides with symmetrical self-locking systems, each having a set of elements automatically blocking the tilting function when the position of the sash is slightly changed versus the window frame due to turning the sash, and a set of elements automatically blocking the turning function when the position of the sash is slightly changed versus the window frame due to tilting the sash. Both blocking systems (11 ) and (21 ), and (12) and (18) are connected together by connecting means, which warrants their alternative action. When the window is closed, the locking elements (12) and (18) of one blocking set are always in mutual contact, but are not blocked in that position, and when starting the usage function the blocking of which they are serving, they play the role of a mechanism forcing the locking of the second usage function of the window by the locking set (11 ) and (21 ). Each self-locking system has also a retaining mechanism, which, when applying the function blocked by the set of elements (11 ) and (21 ), immobilizes the element (12) of the locking set consisting of the elements (12) and (18) staying in mutual contact when the window is closed.