Level 3 or lower monsters are destroyed during the End Phase of the turn that they are Normal Summoned or Flip Summoned.
Rulings
Netrep Rulings
“Infinite Dismissal” does not destroy Level 3 or lower monsters that are removed from the field or turned face down before the End Phase.
Level 3 or lower Spirit Monsters that are summoned while “Infinite Dismissal” is active will return to the hand before “Infinite Dismissal” destroys it if it is the Turn Player's Spirit Monster.
Trap|
Continuous