Greenhouse comprising a roof construction, wherein. the roof construction comprises a slanting upper surface, a first framework that defines a roof opening, and a rectangular ventilation window that covers the roof opening, wherein the ventilation window comprises a panel and a second framework along at least a distal front edge and two parallel side edges of the panel, wherein the greenhouse comprises a netting system to prevent passage of insects through the ventilation passage, wherein the netting system comprises an insect netting that covers the ventilation passage and that is pleated in a bellow configuration to collapse in a stacked manner, and a guiding provision for the insect netting, wherein the guiding provision comprises an elongate guiding bow between the first framework and second framework that extends along the insect netting, wherein the insect netting is slidably connected with the elongate bow.
