A skylight window for being installed in a roof of a building, the skylight window comprising: a window frame having four frame side members, a window sash having four sash side members supporting an Insulating Glazing Unit, abbreviated IGU, having multiple layers of glazing, said window sash being movable in relation to the window frame between an open and a closed position of the skylight window, a weather shield attached to the sash so as to protect a window portion of the skylight window, the window portion comprising the sash, the frame and the IGU, a first of the frame side members being associated with a first of the sash side members, said first frame and sash side members extending in a respective longitudinal direction substantially in parallel with a respective first peripheral side of the IGU, said IGU having an exposed interior major surface for facing an interior of said building in an installed position of the skylight window, said IGU further having an exposed exterior major surface facing in an opposite direction towards an exterior in said installed position of the skylight window, where said weather shield extends across substantially the entire exposed exterior major surface, wherein in a closed position of said skylight window said first sash side member extends in a longitudinal direction substantially in parallel with said first frame side member, said first sash side member having a first leg connected to a supporting section of the first sash side member supporting the IGU, the first leg extending in said longitudinal direction and extending substantially in a height direction substantially perpendicularly to at least one of said major surfaces of the IGU, said first leg having a thickness in a width direction extending perpendicularly to said longitudinal and height directions, characterized in that at least a portion of said first leg of the first sash side member is generally plate-shaped, consisting of one single section of substantially solid material having a said thickness less than 1 cm. a window frame having four frame side members, a window sash having four sash side members supporting an Insulating Glazing Unit, abbreviated IGU, having multiple layers of glazing, said window sash being movable in relation to the window frame between an open and a closed position of the skylight window, a weather shield attached to the sash so as to protect a window portion of the skylight window, the window portion comprising the sash, the frame and the IGU, a first of the frame side members being associated with a first of the sash side members, said first frame and sash side members extending in a respective longitudinal direction substantially in parallel with a respective first peripheral side of the IGU, said IGU having an exposed interior major surface for facing an interior of said building in an installed position of the skylight window, said IGU further having an exposed exterior major surface facing in an opposite direction towards an exterior in said installed position of the skylight window, where said weather shield extends across substantially the entire exposed exterior major surface, wherein in a closed position of said skylight window said first sash side member extends in a longitudinal direction substantially in parallel with said first frame side member, said first sash side member having a first leg connected to a supporting section of the first sash side member supporting the IGU, the first leg extending in said longitudinal direction and extending substantially in a height direction substantially perpendicularly to at least one of said major surfaces of the IGU, said first leg having a thickness in a width direction extending perpendicularly to said longitudinal and height directions, characterized in that at least a portion of said first leg of the first sash side member is generally plate-shaped, consisting of one single section of substantially solid material having a said thickness less than 1 cm.