An image coding apparatus includes a coding unit 100 for generating a code A, a coding unit 110 for generating a code B, an image reproduction unit 200, an image reproduction memory 204, and a motion vector detection unit 300. The motion vector detection unit 300 detects a motion vector using an image in the image reproduction memory 204, whereby the coding unit 100 generates the code A, while the image reproduction unit 200 reconstructs an image on the basis of output from the coding unit 100 and stores the image in the image reproduction memory 204. In the operation for generating the code B, the coding unit 110 is employed as a coding unit for generating the code B, while commonly employing the image reproduction memory 204, the motion vector detection unit 300, and the image reproduction unit 200 as employed in the generation operation for code A.