To provide a fixing device that increases the rising speed of fixing roller surface temperature, shortens a first print time, prevents a half-tone image from being jagged owing to fixation unevenness, and secure peelability of a recording material from a fixing roller.

In the heat fixing device equipped with a heating means of heating the surface of the fixing roller having an elastic layer from outside, a pressure member forming a fixation nip part is formed of a pressure pad which is pressed against the fixing roller through a thin film, and the downstream side of the pressure pad is convex toward the fixing roller to make a pressure distribution in the fixation nip high on the downstream side. Consequently, when the fixing roller surface is strained to heat and fix a thin recording material, peelability of the recording material from the fixing roller is improved during discharge of the recording material from a fixation nip exit to solve the problem that the recording material is wound around the fixing roller.