The teacher's role within a flipped classroom is very different from a traditional teacher's role.  The biggest change in the role of the teacher in a flipped classroom is that the teacher does not stand in front of the students and simply lecture for the class period.  Since students are asked to watch a video and/or read sections of their text before attending class, class time can be used differently.  However, it is the responsibility of the teacher to supply students with meaningful subject matter to explore/watch prior to class (for homework); a popular way to do this is for teachers to create their own instructional videos or locate appropriate ones already online that can be made available for the students to view at home (or at school prior to class).  Click on the flipped apple icon below to explore a variety of videos related to flipped learning and instructional videos created by teachers of flipped classrooms.

     Within the classroom, the teacher's role during class time also changes; he/she becomes a facilitator.  During class time, the teacher helps provide students with activities that allow them to apply the knowledge that they have gained from the work done prior to attending class.  During this time, students interact with one another, the teacher, and the content to complete active, hands-on activities that require students to apply what they have learned.  This way the teacher is available to better support students' active learning and exploration.  There is more time for hands-on projects and activities within the classroom when the "lecturing" (or studying of material) is done outside of the classroom.  

For more information on the topic, check out this article about teacher roles in a flipped classroom.