To provide a fixing device in which the nip width of a heating nip area formed by the contact of an external heating member with a fixing body is easily confirmed, and to provide an image forming apparatus equipped with the fixing device.

The fixing device is equipped with a fixing roller 1 and a pressure roller 4 rotating in press-contact with each other, and an external heating roller 2 coming into contact with the roller 1 to form a nip part 5 and heating the roller 1 from the outside. Recording material carrying an unfixed image is heated and pressed while it is held and fed by the rollers 1 and 4, whereby the unfixed image is fixed on the recording material. A guiding part 10 for guiding a sheet 7 for confirming the nip width 6 of the nip part 5 to the nip part 5 is provided to a stay 8.