A personal identification apparatus is disclosed by which personal identification can be performed making use of an impulse response obtained from a pulse signal transmitted by a living organism. A pulse generation section generates a pulse, and a speaker applies the pulse amplified by an amplifier to a finger of a user touching with the speaker and a microphone. The pulse signal is transmitted to the microphone with an attenuation characteristic that depends upon, for example, a transmission distance that depends upon the length and the thickness of the finger and characteristics of the living organism such as the thickness of the flesh and the bone density. A data synthesis processing section synthesizes the pulse and an impulse received by the microphone and amplified by an amplifier. A template recording section records a template to be used as a reference of discrimination in an authentication process together with a user ID and so forth. A comparison discrimination processing section refers to the template recording section to discriminate whether or not an impulse response inputted from a memory coincides with one of templates of registered users.