An implanted compact antenna for an artificial cardiac pacemaker is proposed. The dimension of the pacemaker system, including the antenna element, is 30mm × 35mm × 7mm. When the antenna is embedded in a semi-solid flat phantom with equivalent electrical properties as the human body, S11 value is -19.2dB at 403.5MHz and the -10dB impedance bandwidth of the antenna is 10MHz (399∼409MHz). The proposed antenna in the phantom has a peak gain of -24.61dBi at 403.5MHz. The measured specific absorption ratio (SAR) value of the proposed antenna is 0.0079W/Kg (1g tissue). Moreover, to estimate the communication performance of the proposed antenna operated in the real environment, a link budget analysis is performed.