A disclosed fixing device for fixing resin particles softened by applying a foam fixer thereon to a recording medium includes a foam fixer generator unit to introduce air bubbles into a liquid fixer containing a softener for softening the resin particles by dissolving or swelling a part of the resin particles to generate the foam fixer, a fixer application member to be brought into contact with a facing member facing the fixer application member to form an application nip and transfer the generated foam fixer to the application nip by moving its surface while carrying the foam fixer to apply the foam fixer to a surface of the recording medium carrying the resin particles at the application nip, and a foam accumulation detector unit to detect a foam accumulation formed of the foam fixer accumulated at an entrance side of the application nip.