WorkSheets = all your Worksheets private void deleteUnUsedWorksheets() { foreach (Excel._Worksheet sheet in WorkSheets) { if (IsWorkbookEmpty(sheet)) sheet.Delete(); } } private bool IsWorkbookEmpty(Excel._Worksheet sheet) { ExcelRange = sheet.UsedRange; if (ExcelRange.Columns.Count > 1 | ExcelRange.Rows.Count > 1 | ExcelRange.Count > 1) return false; else return true; } You dont have to check each cell. Its senseless and you throw a lot of memory Don`t throw a catch if its only a return false!