An image quality/rate control portion 106 confirms whether a predictive code amount Ci is a target code amount Rt or less. When the predictive code amount Ci is the target code amount Rt or less, the predictive code amount Ci is output to a base layer coding portion 101. Then, a switch 108 is turned off. When the predictive code amount Ci exceeds the target code amount Rt, the target code amount Rt is output to the base layer coding portion 101. Then, the switch 108 is turned on and (predictive code amount Ci−target code amount Rt) is output to an enhancement layer coding portion 103. A buffer 104 stores coded data of the base layer coding portion 101 and the enhancement layer coding portion 103. In this manner, while performing fixed bit rate coding using a single transmission path, image quality of a moving image is made constant so as to prevent deterioration of image quality.