Excel processes kept running

I have an application that creates, sets values and formats worksheets in an excel workbook.
The application works fine.
I post hereunder some code (manually typed) showing how I access the worksheets.
I have many routines accessing different/same worksheets.
These routines are activated separately from a menu.
The real code includes exception handling and recovery but I didnt include those parts for clarity.
The problem is that once one of these routines ends the excel process is not freed and stays in memory!
Meaning that while the application is still working I have many Excel processes running consuming memory.
Each time the user activates one of these routines I have another Excel process in memory.
These processes are removed from memory only when I close my application.

Of course i can use one object to create the Excel Application and use it to open the workbooks and worksheets but I want to understand what I am doing wrong here where each subroutine opens her own Excel Application and "supposely" closes it.

    Imports Excel

    Dim xlApp As Global.Excel.Application
    Dim xlWkb As Global.Excel.Workbook
    Dim report As Worksheet

    'Create the excel application
    xlApp = CreateObject("Excel.Application")

     'Add the workbook to the excel application
     xlWkb = xlApp.Workbooks.Open("C:\MyFile.xls")
 
     report = xlWkb.Worksheets("Sheet1")

    With report
       <... excel formating and value assignments code here >
    End With

    xlWkb.Save()
    xlWkb.Close()
    xlApp.Quit()Start Free Trial