The present disclosure proposes a receiving device, an abnormality detecting method, and an abnormality detecting program, which are capable of detecting an abnormality related to a reference signal after the reference signal is outputted. The receiving device includes an output part, an input part, and processing circuitry. The output part outputs a first signal that is a periodical reference signal generated based on a positioning signal to a first transmission line connected to an external device. The input part accepts an input of a second signal that is a returning signal of the first signal of the first transmission line from the external device side via a second transmission line. The processing circuitry detects an abnormality related to the reference signal based on a signal characteristic of the second signal.