To avoid the breakage of reproduced data by outputting only the normal data when abnormal data are detected in a signal reproduction mode.

When abnormality of digital data is detected by a detection means, it is inhibited to use the data on the AC coefficients which are arrayed after the data whose abnormality is detected in a rectangular block as well as the data whose abnormality is detected by the detection means. In this device, if abnormality of a variable length code is detected at a decoding part 10a, an error control part 11c outputs the H signals for a period covering a point of time when an error is detected through a point of time when the final part of a DCT block where the error data exist is decoded. During this period, a switch 11f outputs selectively the O code. Accordingly when errors exist in variable length codes at the error occurring part and in variable length codes of a higher band, these errors will not be reproduced as normal data.