PROBLEM TO BE SOLVED: To provide an image decoding apparatus for decoding variable length encoded image data at high speed while suppressing an increase in a circuit area. SOLUTION: Each of first-third decoding parts 100-300 is provided with a comparator, a decoder and a code word table. The code word table 130 has the MPEG code word table of "RUN=0", and the code word tables 230 and 330 have the MPEG code word table of "RUN≠0". In the first decoding part 100, the comparator 110 compares an input variable length code bit string with the variable length code word of the code word table 130, and the decoder 120 outputs a decoded result corresponding to a matching variable length code word to an output part 30. The second decoding part 200 and the third decoding part 300 decode two variable length code words in one machine cycle by utilizing a shift part 20. COPYRIGHT: (C)2007,JPO&INPIT