The present invention relates to an electrocardiogram measurement apparatus (measurement sensor) which can be used in combination with a smartphone by an individual. The electrocardiogram measurement apparatus according to the present invention comprises: two amplifiers for receiving electrocardiogram signals from a first electrode and a second electrode; one electrode driving unit; a third electrode for receiving an output of the electrode driving unit; an A/D converter connected to an output terminal of each of the two amplifiers and converting analog signals into digital signals; a microcontroller for receiving the digital signals from the A/D converter; and a communication means for transmitting the digital signal, wherein: the microcontroller is supplied with power from a battery; the microcontroller controls the A/D converter and the communication means; and each of the two amplifiers amplifies one electrocardiogram signal so as to simultaneously measure two electrocardiogram signals.