A cam data display device is designed to perform waveform display of a motion of an electronic cam and is provided with a cam-shape data storage unit configured to store cam-shape data in which a phase of a camshaft is associated with a position of a slave axis, a camshaft rotational speed acquisition unit configured to acquire a rotational speed of the camshaft, and a waveform generation unit configured to generate the waveform display indicative of the relationship between time and the motion of the slave axis, based on the cam-shape data and the rotational speed of the camshaft.