The sample demonstrates how to export doc document to Epub file.

using Spire.Doc;

namespace DocToEpub
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create word document
            Document doc = new Document();
            doc.LoadFromFile(@"..\..\..\..\..\..\Data\DocToEpub.docx", FileFormat.Docx);
            doc.SaveToFile(@"DocToEupb.epub",FileFormat.EPub);
            System.Diagnostics.Process.Start(@"DocToEupb.epub");
        }
    }
}

Imports Spire.Doc

Namespace DocToEpub
	Friend Class Program
	Shared Sub Main(ByVal args() As String)
        'Create word document
	Dim doc As New Document()
	doc.LoadFromFile("..\..\..\..\..\..\Data\DocToEpub.docx",FileFormat.Docx)
	doc.SaveToFile("DocToEupb.epub",FileFormat.EPub)
	Process.Start("DocToEupb.epub")
	End Sub
	End Class
End Namespace