A moving picture coding apparatus (10a) according to the present invention includes a level analyzer (100a) that decides the maximum number of intra frame pixels which can be coded (Nfpx) and the maximum number of storage pixels which can be stored in a picture memory of a decoding apparatus (Nspx) on the basis of a level identifier (Lst) indicating a coding level that is designated by the user, thereby judging whether coding of an input image is possible or not and calculating the maximum number of reference pictures (Nrpn) as the number of reference candidate pictures which can be referred to at inter picture prediction coding, on the basis of the maximum number of intra frame pixels (Nfpx) and the input image size (the number of vertical pixels (Nhpx) and the number of horizontal pixels (Nwpx)). A decoding apparatus to which a bit stream from the moving picture coding apparatus (10a) is supplied can always decode the bit stream satisfactorily, and perform inter picture prediction decoding corresponding to the inter picture prediction coding on the coding end. Consequently, memory areas of a coding apparatus and a decoding apparatus that are adapted to a coding method in which there is no restraint on the capacity of the memory area can be designed.