A method for searching for a telephone number and performing a function using the detected telephone number on a mobile terminal, the method comprising: a) checking whether an entry by a user in a standby mode is at least one alphanumeric character or alphabetical character; b) searching a telephone number database for at least one telephone number including all of the alphanumeric characters being entered in the standby state, every time at least one alphanumeric character is entered when the entry by the user is an alphanumeric character; c) searching a telephone number database for at least one telephone number corresponding to names including all of the alphabetical characters being entered in the standby state, every time at least one alphabetical character is entered when the entry by the user is an alphabetical character; d) displaying the at least one telephone number and displaying a menu of functions available using a selected one of the displayed telephone numbers, wherein step b) includes: searching the telephone number database to detect at least one telephone number having the same alphanumeric character and displaying detected telephone numbers, when a first alphanumeric character is entered by the user; receiving an N th alphanumeric character, with N ≥ 2 representing the order of the input of the alphanumeric character by the user, detecting telephone numbers having the same N th alphanumeric character from the previously detected telephone numbers and displaying the newly detected telephone numbers; and repeating the receiving, detecting and displaying step, and wherein step c) includes: searching the telephone number database to detect names according to a first alphabetical character by the user and displaying the detected names and their corresponding telephone numbers; receiving an N th alphabetical character, with N ≥ 2 representing the order of input of the alphabetical character by the user, detecting names having an identical N th alphabetical character from the previously detected names and displaying the newly detected names and their corresponding telephone numbers; and repeating the receiving, detecting and displaying step. a) checking whether an entry by a user in a standby mode is at least one alphanumeric character or alphabetical character; b) searching a telephone number database for at least one telephone number including all of the alphanumeric characters being entered in the standby state, every time at least one alphanumeric character is entered when the entry by the user is an alphanumeric character; c) searching a telephone number database for at least one telephone number corresponding to names including all of the alphabetical characters being entered in the standby state, every time at least one alphabetical character is entered when the entry by the user is an alphabetical character; d) displaying the at least one telephone number and displaying a menu of functions available using a selected one of the displayed telephone numbers, searching the telephone number database to detect at least one telephone number having the same alphanumeric character and displaying detected telephone numbers, when a first alphanumeric character is entered by the user; receiving an N th alphanumeric character, with N ≥ 2 representing the order of the input of the alphanumeric character by the user, detecting telephone numbers having the same N th alphanumeric character from the previously detected telephone numbers and displaying the newly detected telephone numbers; and repeating the receiving, detecting and displaying step, searching the telephone number database to detect names according to a first alphabetical character by the user and displaying the detected names and their corresponding telephone numbers; receiving an N th alphabetical character, with N ≥ 2 representing the order of input of the alphabetical character by the user, detecting names having an identical N th alphabetical character from the previously detected names and displaying the newly detected names and their corresponding telephone numbers; and repeating the receiving, detecting and displaying step.