An image forming apparatus including a fixing device to fix a toner image on a recording medium including a heat roller and an oil applicator to apply a silicone oil to the heat roller, having a system speed of from 500 to 1700 mm/sec, and using a toner including a binder resin including a crystalline polyester resin and an amorphous polyester resin; a fatty acid amide compound; and a colorant, wherein a ratio (W/R) of a height (W) of a peak at a wavenumber of 1638 cm.sup.-1, specific to the fatty acid amide compound, to a height (R) of a peak at a wavenumber of 829 cm.sup.-1, specific to the amorphous polyester resin, is from 0.010 to 0.040 in an absorption spectrum obtained by an ATR method (total reflectance method) using a Fourier transform infrared (FT-IR) spectrophotometer.