A fixing apparatus that fixes an image onto a recording material includes: a belt; a nip plate contacting an inner surface of the belt; a roller configured to form a nip portion with the nip plate; a supporting member supporting the nip plate, the supporting member having a cross section in a shape of U, and supporting, with two legs, a surface of the nip plate opposite to a surface contacting the belt; and a guide member disposed on an upstream side of the nip plate and including a guide portion, wherein the recording material on which the image is formed is heated while being conveyed through the nip portion, and the image is fixed onto the recording material, and the guide member is supported by a first surface and a second surface of an upstream side leg among the two legs of the supporting member.