An image forming apparatus includes a carriage that includes a head including a black nozzle array in which a plurality of nozzles are arranged and a color nozzle array in which a plurality of nozzles are arrange, the black nozzle array being disposed at a position shifted in the sub-scanning direction downstream in a medium conveying direction with respect to the color nozzle array; a conveying unit configured to convey a recording medium in a sub-scanning direction; and a control unit. The control unit forms an image by the color nozzle array in a main scanning in one direction, relatively moves the recording medium to a subsequent main-scanning position thereafter, and forms an image by the black nozzle array on the image formed by the color nozzle array in a following main scanning in the other direction so as to complete an image for one scanning area.