A fixing device includes a fixing member, a pressing member and a separating member. The fixing member is provided with a sheet passing region through which a recording medium is passed and a non-sheet passing region arranged outside the sheet passing region. The pressing member comes in pressure-contact with the fixing member to form a fixing nip. The separating member is configured to separate the recording medium passed through the fixing nip from the fixing member. The separating member has a separating plate and a restricting piece. The separating plate faces the sheet passing region with an interval. The restricting piece restricts the interval. The restricting piece is provided with a contacting surface which comes in contact with the non-sheet passing region. The contacting surface has a width which becomes wider from an upstream side to a downstream side in the rotation direction of the fixing member.