Abstract: In multi-connections, a message writing apparatus is provided. This message writing apparatus (21) comprises a path recognizing section (21a), a received message assembling section (21b), a receive control section (21c), an arbitrating section (21d) and an external memory control section (21e). When a received ATM cell is written/readout in/from a receiving buffer, it is written/read out in a memory area corresponding to each path, which enables the processing of AAL5 messages from a plurality of paths and improves the transfer processing capability, thereby leading to realizing a shortening of the data transfer time.