To provide a ventilation structure of an indoor opening, which enables ventilation and the interruption of the ventilation to be performed by a sliding door and a vertical blind, provided in an opening for making rooms communicate with each other indoors, which enables adjustment for making an opening area of the opening large or small on the basis of a relationship with light and/or a line of sight, which can prevent the interior of the room from being narrowed with the sliding door and the vertical blind, and which enables the easy performance of the opening and closing operations of the sliding door.

In the opening 4 for the ventilation, the sliding door 5 for interrupting the ventilation, and the vertical blind 6 are provided in a horizontally serial state. The sliding door and the vertical blind are interlocked with each other. When the opening is opened by making the sliding door recede from the side of the opening, the vertical blind is spread to the side of the opening. When the opening is closed by making the sliding door advance to the side of the opening, the vertical blind is folded.