A frame synchronization apparatus (10) according to this invention includes a multiplication unit (11) configured to multiply a received signal by an inverse complex number of a predetermined synchronization pattern with respect to a predetermined signal point on a complex space diagram for each of a plurality of symbols of the received signal, an addition average unit (12) configured to perform addition averaging of outputs from the multiplication unit for the plurality of symbols of the received signal, and a synchronization determination unit (13) configured to perform coincidence determination of whether an output from the addition average unit (12) falls within a predetermined coincidence determination range of the predetermined signal point, and determine a synchronization state of the frame synchronization based on a result of the coincidence determination. According to this invention, it is possible to provide a frame synchronization apparatus that correctly determines a synchronization state even if an error rate of received symbols is high.