I found the solution. This is the peace of code which loop trough the all embedded fields:
public void loopFileds(ItemField field)
if(field.FieldType.Equals(Tridion.ContentManager.Interop.TDSDefines.EnumTridionWebSchemaFieldType.FieldTypeEmbed))
{
ItemFields embeddedFileds = field.value[1] as ItemFields;
if (embeddedFileds != null)
{
foreach (ItemField item in embeddedFileds)
{
// recursive call to pass through all embedded fields with the custom depth
loopFileds(item);
}
}
}