An agricultural greenhouse includes a house body and a curtain arranged along a roof inside the house body. The curtain is supported by a support part extended in the depth direction (Y-axis direction) of the house body and is configured be opened and closed in the depth direction along the support part. One end in the depth direction is a fixed end, and the other end is a free end. The curtain is opened and closed in the depth direction along the support part by fixing the fixed end at a regular position and moving the free end in the depth direction with movement of a pulley moving on the support part. Therefore, the curtain is in full-opened state when the free end is closest to the fixed end, and is in full-closed state when the free end is farthest away from the fixed end.
