1. An information recording device comprising: a coder for coding an inputted information signal; a rate controller for controlling a coding rate of the coder in accordance with complexity of the information signal and controlling a coding amount per unit time in the coding process so that an average value of the coding amount can be approximate to an average rate which is previously set; a temporary memory unit for temporarily memorizing the coded data; and a recorder for recording the data memorized in the temporary memory unit on a recording medium, wherein the recorder measures a recording rate in the recording process, the rate controller adjusts the average rate to be below the recording rate measured by the recorder such that the coding amount to be allocated to a high complexity region of the information signal increases, while the coding amount to be allocated to a less complexity region of the information signal is reduced, when the recorder detects that the recording medium as a current recording object is exchanged, the recorder informs the rate controller of the exchange, and the rate controller resets the average rate to an initial value which is previously set when the rate controller receives the notice of the exchange of the recording medium.