To provide a partition wall structure equipped with a ventilation louver, which suppresses deterioration of the design of the partition wall due to the ventilation louver and facilitates installation of the ventilation louver.

A partition wall 13 is formed of a plurality of partition wall panels 15. The partition wall panel 15 comprises a base frame 24 consisting of a vertical bar 26 and a horizontal bar 27, and a pair of wall face members disposed as sandwiching the base frame 24. On a ventilation wall panel 15a among the plurality of partition wall panels 15, a ventilation opening part 17 that penetrates the ventilation wall panel 15a in the thickness direction is formed. In a base frame 24a of the ventilation wall panel 15a, the pair of horizontal bars 27 that vertically sandwich the ventilation opening part 17 serve as a pair of ventilation frame members 31. The ventilation frame member 31 is made so that its dimension in the wall thickness direction is smaller than that of the vertical bar 26, and in the ventilation opening part 17, a pair of ventilation louvers 18 are installed as sandwiching the frame members 31 from both sides.