To provide a form structure-cum-decorative plate member wherein a large stone material or the like is used also as a form, so as to complete a wall face decoration as well as to finish a concrete wall face while reliably withstanding the load of placed concrete.

The form structure-cum-decorative plate member comprises: stone material plates 1, 1, ..., arranged instead of a surface side form member; upright support members 2, 2, ..., arranged at the back of vertical joints so as to allow the stone material plates to be connected to the front faces of connection pieces 2a, 2a; holding members 3, 3, ..., arranged in front of the stone materials 1, 1, ...; mounting members 4, 4, ..., for detachably bonding the holding members 3, 3, ..., to the upright support members 2, 2, ..., through the vertical joints of the stone material plates 1, 1, ..., to fix the holding members in that state; a bonding member 5 for being locked in locking grooves 1a, 1b at the upper and lower ends of the stone material plates 1, 1, ...; a form member 8 arranged on the back side of the stone materials 1, 1, ...; and an interval holding means 9 for bonding the form member 8 to the upright support members 2, 2, ....