A fixing device having: a heating unit; a first rotating member and rotating in a first rotational direction; a second rotating member contacting the first rotating member and thereby forming a nip through which a printing medium passes, wherein the second rotating member rotates in a second rotational direction opposite to the first rotational direction; a reflective member provided around the first rotating member and having a reflection surface provided so as to face the first rotating member; and an inhibitory member inhibiting air in a space between the reflective member and the first rotating member from flowing out through a first gap between a downstream end of the reflective member in the first rotational direction and a closest portion of the first rotating member to the downstream end of the reflective member, wherein the inhibitory member overlaps with a part of the first gap.