What is the correct way to get the Series of a char in PPT 2010. I tried PowerPoint.SeriesCollection mySeriesCollection = (PowerPoint.SeriesCollection) myChart.SeriesCollection(1); throws the following exception Exception Type: System.InvalidCastException Further, What is the correct call in C# to get the series of a chart ? If I try this way: PowerPoint.Series mySeries = (PowerPoint.Series)myChart.SeriesCollection.Item(1); I get the following compile error : error CS0119: 'Microsoft.Office.Interop.PowerPoint.Chart.SeriesCollection(object)' is a 'method', which is not valid in the given context