PURPOSE: To attain registration without mis-depression of a number with a simple operation of depressing two buttons of a registration button operated when the registration of a caller number is instructed and an abbreviation dial button to select an abbreviation dial storage memory used to register the caller number.

CONSTITUTION: The telephone set is provided with an I interface section 1 interfacing an external device and a central controller 2 controlling the entire of the abbreviation dial telephone set and receiving and outputting a caller number from the I interface section 1, with a caller number storage memory 3 storing tentatively the caller number outputted from the central controller 2 and with a registration button 4 operated when the registration of a caller number is commanded, and also with an abbreviation dial storage memory 5 storing the caller number and an abbreviation dial button 6 selecting the abbreviation dial storage memory 5.