PURPOSE: To prevent the deterioration of processing ability by permitting an additional service control means to manage a part of information required for the decision and execution for additional service.

CONSTITUTION: When a basic call control processing part 31 detects the possibility of starting the additional service, an additional information collection management part 231 selects a reference additional information type list 232 to record the time used for the reference additional information type list 232. Then the additional information indicated in the reference additional information type list 232 is read out from the basic call control data part 32 and the additional information lacking in the additional service analysis part 21 is inquired at an additional service additional information collection part 23. The additional information collection management part 231 reads the additional information from the basic call control part 32, counts the number of times of of reading for each additional information in an additional information collection learning logic 233 to be compared with the threshold value to be added to the reference additional information type list. In the case of a counted value exceeding the threshold value, the type of the reference additional information is added on the reference additional information list, thereby resetting the threshold value.