A fixing device includes a fixing belt, a heater, a nip plate, a pressure roller, a stay, a cover, and a spring. The fixing belt has an inner surface. The heater is configured to heat the fixing belt. The nip plate is configured to contact the inner surface. The pressure roller is configured to press the fixing belt in cooperation with the nip plate. The stay is provided at a position opposite to the pressure roller with respect to the nip plate. The stay is configured to receive a force applied to the nip plate from the pressure roller. The cover is configured to cover the stay. The spring includes a first portion configured to urge the stay to the cover, and a second portion configured to urge the cover to the stay.