A Fauquier County Circuit Court judge today threw out a lawsuit by a wealthy landowner seeking to close down a newly opened inn in the farming village of Paris.

Judge William Shore Robertson said the county Board of Supervisors' decision to grant permission for the inn to operate was shielded by a "presumption of reasonableness."

Robertson said C. Reed Thomas, the landowner who sued the county and the inn's owners, failed to prove that the county board acted incorrectly in allowing the Ashby Inn permission to operate. It is located in Paris, off U.S. Rte. 17 about 55 miles west of the District.

Thomas, who was not in court and has refused to comment on the case, owns about 1,800 acres in the area, virtually surrounding Paris.

"It's going to be nice to move from legal abstractions . . . to hard words like Bass Ale and steak and mushroom pie," said John L. Sherman, who with his wife, Roma, owns the inn. Sherman is press secretary for the House Ways and Means Committee and his wife is an advertising executive in the District.

Thomas' lawyer, Robert A. Niles, said that Thomas had expressed interest in appealing to the state Supreme Court. But Niles conceded that Thomas' case was handicapped by the tendency of Virginia courts to presume that local governments have acted reasonably.

The Ashby Inn, which opened for business last month, has six bedrooms. The Shermans spent about $400,000 buying and renovating the inn. Currently open for guests only on the weekends, a room at the inn costs $70 to $100 a night.

Inn opponent Thomas "will get an invitation to have a meal with us tomorrow," John Sherman said after yesterday's court action.