Since 1984, the Mark I mobile robot for finishing concrete floor slabs has been at construction sites. This operation has confirmed the robots constant finishing accuracy, high efficiency, and savings in night-shift manpower through its use. The previous report discussed the robots effectiveness as a replacement for plasterers. Since then, the operation results of the Mark I have been analyzed and used to develop an improved version, the Mark II, in 1986. This report describes the Mark II and describes the results of its use. The Mark II is a compact robot with excellent operability, and is well-suited to construction-site work .It has met our development objectives. The Mark II robot is now technically completed and gas gone into use by plasterers. So far its operation results are promising, and it is likely to come into widespread practical use.